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Professor Jeffrey Tostevin


Emeritus Professor of Physics
+44 (0)1483 686784
09 BB 03

Academic and research departments

Department of Physics.

My publications

Publications

McDaniel S, Gade A, Tostevin JA, Baugher T, Bazin D, Brown BA, Cook JM, Glasmacher T, Grinyer GF, Ratkiewicz A, Weisshaar D (2012) Intermediate-energy inverse-kinematics one-proton pickup reactions on neutron-deficient f p-shell nuclei,PHYSICAL REVIEW C 85 ARTN 014610 American Physical Society
Background: Thick-target-induced nucleon-adding transfer reactions onto energetic rare-isotope beams are an emerging spectroscopic tool. Their sensitivity to single-particle structure complements one-nucleon removal reaction capabilities in the quest to reveal the evolution of nuclear shell structure in very exotic nuclei. Purpose: Our purpose is to add intermediate-energy, carbon-target-induced one-proton pickup reactions to the arsenal of ³-ray-tagged direct reactions applicable in the regime of low beam intensities and to apply these for the first time to fp-shell nuclei. Methods: Inclusive and partial cross sections were measured for the 12C(48Cr,49Mn+³)X and 12C(50Fe,51Co+³)X proton pickup reactions at 56.7 and 61.2 MeV/nucleon, respectively, using coincident particle-³ spectroscopy at the National Superconducting Cyclotron Laboratory. The results are compared to reaction theory calculations using fp-shell-model nuclear structure input. For comparison with our previous work, the same reactions were measured on 9Be targets. Results: The measured partial cross sections confirm the specific population pattern predicted by theory, with pickup into high-? orbitals being strongly favored, driven by linear and angular momentum matching. Conclusion: Carbon-target-induced pickup reactions are well suited, in the regime of modest beam intensity, to study the evolution of nuclear structure, with specific sensitivities that are well described by theory.
Bartlett AJ, Tostevin JA, Thompson IJ (2008) R-matrix and dynamical model calculations of three-body resonance decay widths,PHYSICAL REVIEW C 78 (5) ARTN 054603 AMER PHYSICAL SOC
Tostevin JA, Bazin D, Brown BA, Glasmacher T, Hansen PG, Maddalena V, Navin A, Sherrill BM (2002) Single-particle spectroscopy of rare isotope beams: Calculations beyond the eikonal approximation,NUCLEAR PHYSICS IN THE 21ST CENTURY 610 pp. 653-657 AMER INST PHYSICS
The momentum distributions of the residual nuclei after one-neutron removal, measured in coincidence with gamma rays, identify the excited levels of these residues. The resulting differential partial cross sections map the momentum content and structure of the removed-nucleon wave function and provide an exacting test of theory. Data for population of the C-14 and Be-10 ground states show an asymmetry that is incompatible with the currently used eikonal descriptions. A fully dynamical description of the elastic break-up mechanism provides an understanding of the new observation, which will be most pronounced for nuclear halo states, This interpretation is clarified by an analysis of the angular distribution of the heavy residues.
Peters WA, Baumann T, Brown BA, Brown J, DeYoung PA, Finck JE, Frank N, Jones KL, Lecouey J-L, Luther B, Peaslee GF, Rogers WF, Thoennessen M, Tostevin JA (2012) Reply to "Comment on 'Neutron knockout of Be-12 populating neutron-unbound states in Be-11' ",PHYSICAL REVIEW C 86 (1) ARTN 019802 AMER PHYSICAL SOC
Kobayashi N, Nakamura T, Kondo Y, Tostevin JA, Aoi N, Baba H, Barthelemy R, Famiano MA, Fukuda N, Inabe N, Ishihara M, Kanungo R, Kim S, Kubo T, Lee GS, Lee HS, Matsushita M, Motobayashi T, Ohnishi T, Orr NA, Otsu H, Sako T, Sakurai H, Satou Y, Sumikama T, Takeda H, Takeuchi S, Tanaka R, Togano Y, Yoneda K (2016) One-neutron removal from Ne29: Defining the lower limits of the island of inversion,Physical Review C: Nuclear Physics 93 014613
Background: Very neutron-rich isotopes, including Ne30-32, in the vicinity of N=20 are known to exhibit ground states dominated by fp-shell intruder configurations: the ?island of inversion.? Systematics for the Ne-isotopic chain suggest that such configurations may be in strong competition with normal shell-model configurations in the ground state of Ne29.
Purpose: A determination of the structure of Ne29 is thus important to delineate the extent of the island of inversion and better understand structural evolution in neutron-rich Ne isotopes. This is accomplished here through a combined investigation of nuclear and Coulomb-induced one-neutron removal reactions.
Method: Cross sections for one-neutron removal on carbon and lead targets and the parallel momentum distribution of the Ne28 residues from the carbon target are measured at around 240 MeV/nucleon. The measurements are compared with reaction calculations combined with spectroscopic information from SDPF-M shell-model wave functions.
Results: The deduced width of the inclusive parallel momentum distribution, 98(12) MeV/c (FWHM), suggests that the ground state of Ne29 has a spin parity of 3/2-. Detailed comparisons of the measured inclusive and partial cross sections of the two targets and the parallel momentum distribution of the carbon target with reaction calculations, combined with spectroscopic information from large-scale shell-model calculations, are all consistent with a 3/2- spin-parity assignment.
Conclusions: The results indicate that Ne29 lies within the island of inversion and that the ground state of Ne29 is dominated by a Ne28(0+1)xp3/2 neutron configuration. Combined with recently measured interaction cross sections, it is concluded that Ne29 may exhibit a moderately developed halo-like distribution
Nakamura T, Kobayashi N, Kondo Y, Satou Y, Tostevin JA, Utsuno Y, Aoi N, Baba H, Deguchi S, Fukuda N, Gibelin J, Inabe N, Ishihara M, Kameda D, Kawada Y, Kubo T, Motobayashi T, Motobayashi T, Orr NA, Otsu H, Otsuka T, Sakurai H, Sumikama T, Takeda H, Takeshita E, Takechi M, Takeuchi S, Tanaka KN, Tanaka N, Togano Y, Yoneda K (2014) Deformation-driven p-wave Halos at the Drip-line: 31Ne,Physical Review Letters 112 142501 American Physical Society
The halo structure of Ne31 is studied using 1n-removal reactions on C and Pb targets at 230 MeV/nucleon. A combined analysis of the cross sections of these nuclear and Coulomb dominated reactions that feed directly the Ne30 ground-state reveals Ne31 to have a small neutron separation energy, 0.15+0.16?0.10 MeV, and spin-parity 3/2?. Consistency of the data with reaction and large-scale shell-model calculations identifies Ne31 as deformed and having a significant p-wave halo component, suggesting that halos are more frequent occurrences at the neutron drip line.
TOSTEVIN J (1983) (D,ALPHA) REACTION AND THE ALPHA-PARTICLE D-STATE,PHYS REV C 28 (2) pp. 961-964 AMERICAN PHYSICAL SOC
Simpson EC, Navratil P, Roth R, Tostevin JA (2012) Microscopic two-nucleon overlaps and knockout reactions from 12C,Physical Review C: Nuclear Physics 86 (5) 054609 American Physical Society
The nuclear structure dependence of direct reactions that remove a pair of like or unlike nucleons from a fast 12C projectile beam are considered. Specifically, we study the differences in the two-nucleon correlations present and the predicted removal cross sections when using p-shell shell-model and multi-?É no-core shell-model (NCSM) descriptions of the two-nucleon overlaps for the transitions to the mass A=10 projectile residues. The NCSM calculations use modern chiral two-nucleon and three-nucleon (NN+3N) interactions. The np-removal cross sections to low-lying T=0, 10B final states are enhanced when using the NCSM two-nucleon amplitudes. The calculated absolute and relative partial cross sections to the low-energy 10B final states show a significant sensitivity to the interactions used, suggesting that assessments of the overlap functions for these transitions and confirmations of their structure could be made using final-state-exclusive measurements of the np-removal cross sections and the associated momentum distributions of the forward traveling projectile-like residues.
Enders J, Bauer A, Bazin D, Bonaccorso A, Brown BA, Glasmacher T, Hansen PG, Maddalena V, Miller KL, Navin A (2002) Single-neutron knockout from 34,35Si and 37S,Physical Review C - Nuclear Physics 65 (3) pp. 343181-3431810 The American Physical Society
CRESPO R, JOHNSON RC, TOSTEVIN JA (1992) MULTIPLE-SCATTERING THEORY OF PROTON ELASTIC-SCATTERING AT INTERMEDIATE ENERGIES,PHYSICAL REVIEW C 46 (1) pp. 279-297 AMERICAN PHYSICAL SOC
LAID A, TOSTEVIN JA, JOHNSON RC (1993) DEUTERON BREAKUP EFFECTS IN TRANSFER-REACTIONS USING A WEINBERG STATE EXPANSION METHOD,PHYSICAL REVIEW C 48 (3) pp. 1307-1317 AMERICAN PHYSICAL SOC
Thompson IJ, Danilin BV, Mortimer J, Tarutina T, Tostevin JA (2004) Threshold and continuum structures in exotic nuclei,NEW ERA OF NUCLEAR STRUCTURE PHYSICS pp. 107-113 WORLD SCIENTIFIC PUBL CO PTE LTD
The role of continuum states in nuclei is considered, along with use of breakup theories of stripping and diffractive dissociation in probing nuclear structure. In the breakup of three-body nuclei such as Borromean halo systems, both three-body and two-body continuum final states need to be modelled and measured.
Maddalena V, Aumann T, Bazin D, Brown BA, Caggiano JA, Davids B, Glasmacher T, Hansen PG, Ibbotson RW, Navin A, Pritychenko BV, Scheit H, Sherrill BM, Steiner M, Tostevin JA, Yurkon J (2001) Single-neutron knockout reactions: Application to the spectroscopy of C-16,C-17,C-19,PHYSICAL REVIEW C 63 (2) ARTN 024613 AMERICAN PHYSICAL SOC
Johnson RC, AlKhalili JS, Tostevin JA (1997) Elastic scattering of halo nuclei,PHYS REV LETT 79 (15) pp. 2771-2774 AMERICAN PHYSICAL SOC
NISHIOKA H, TOSTEVIN JA, JOHNSON RC, KUBO KI (1984) PROJECTILE EXCITATION AND STRUCTURE EFFECTS IN LI-6 AND LI-7 SCATTERING, NUCLEAR PHYSICS A 415 (2) pp. 230-270 ELSEVIER SCIENCE BV
JOHNSON RC, STEPHENSON EJ, TOSTEVIN JA (1989) NATURE OF THE AMPLITUDES MISSING FROM ADIABATIC DISTORTED-WAVE MODELS OF MEDIUM ENERGY (D,P) AND (P,D) REACTIONS, NUCLEAR PHYSICS A 505 (1) pp. 26-66 ELSEVIER SCIENCE BV
CUPPS VR, BROWN JD, FOSTER CC, JONES WP, MILLER DW, NANN H, SCHWANDT P, STEPHENSON EJ, TOSTEVIN JA (1987) THE SN-116(D,P)SN-117 L =0 REACTION-MECHANISM AT INTERMEDIATE ENERGIES, NUCLEAR PHYSICS A 469 (3) pp. 445-466 ELSEVIER SCIENCE BV
Tostevin JA, Al-Khalili JS, Zahar M, Belbot M, Kolata JJ, Lamkin K, Morrissey DJ, Sherrill BM, Lewitowicz M, Wuosmaa AH (1997) Elastic and quasielastic scattering of He-8 from C-12,PHYSICAL REVIEW C 56 (6) pp. R2929-R2933 AMERICAN PHYSICAL SOC
Tostevin JA (2012) Probing the states of nucleons in exotic nuclei,Journal of Physics Conference Series 381
Many of the most exotic neutron-proton asymmetric nuclei are produced in relatively small numbers in high-energy fragmentation reactions. They are produced as fast secondary beams with energies of 100 MeV per nucleon or more. Developments made and recent results that both exploit and assess fast one- and two-nucleon removal reactions from such secondary beams are reviewed. This includes very recent work that interfaces the sudden, eikonal reaction models used with more ab-initio nuclear structure inputs. The potential use of neutron pick-up reactions to study particle-like states in exotic nuclei is also outlined.
Davids B, Austin SM, Bazin D, Esbensen H, Sherrill BM, Thompson IJ, Tostevin JA (2001) Electromagnetic dissociation of 8B and the rate of the 7Be(p, ³)8B reaction in the sun,Physical Review C - Nuclear Physics 63 (6) pp. 658061-6580614 The American Physical Society
Fridmann J, Wiedenhover I, Gade A, Baby LT, Bazin D, Brown BA, Campbell CM, Cook JM, Cottle PD, Diffenderfer E (2005) 'Magic' nucleus Si-42,NATURE 435 (7044) pp. 922-924 NATURE PUBLISHING GROUP
Reifarthl R, Altstadt S, Goebell K, Heftrich T, Heil M, Koloczek A, Langer C, Plag R, Pohl M, Sonnabend K, Weigand M, Adachi T, Aksouh F, Al-Khalili J, AlGarawi M, AlGhamdi S, Alkhazov G, Alkhomashi N, Alvarez-Pol H, Alvarez-Rodriguez R, Andreev V, Andrei B, Atar L, Aumann T, Adeichikov V, Bacri C, Bagchi S, Barbieri C, Beceiro S, Beck C, Beinrucker C, Belier G, Bemmerer D, Bendel M, Benlliure J, Benzoni G, Berjillos R, Bertini D, Bertulani C, Bishop S, Blasi N, Bloch T, Blumenfeld Y, Bonaccorso A, Boretzky K, Botvina A, Boudard A, Boutachkov P, Boztosun I, Bracco A, Brambilla S, Briz Monago J, Caamano M, Caesar C, Camera F, Casarejos E, Catford W, Cederkall J, Cederwall B, Chartier M, Chatillon A, Cherciu M, Chulkov L, Coleman-Smith P, Cortina-Gil D, Crespi F, Crespo R, Cresswell J, Csatlos M, Dechery F, Davids B, Davinson T, Derya V, Detistov P, Diaz Fernandez P, DiJuliot D, Dmitry S, Dore D, Duenas J, Dupont E, Egelhof P, Egorova I, Elekes Z, Enders J, Endres J, Ershov S, Ershova O, Fernandez-Dominguez B, Fetisov A, Fiori E, Fomichev A, Fonseca M, Fraile L, Freer M, Friese J, Borge MG, Galaviz Redondo D, Gannon S, Garg U, Gasparic I, Gasques L, Gastineau B, Geissel H, Gernhaeuser R, Ghosh T, Gilbert M, Glorius J, Golubev P, Gorshkov A, Gourishett A, Grigorenko L, Gulyas J, Haiduc M, Hammache F, Harakeh M, Hass M, Heine M, Hennig A, Henriques A, Herzberg R, Holl M, Ignatov A, Ignatyuk A, Ilieva S, Ivanov M, Iwasa N, Jakobsson B, Johansson H, Jonson B, Joshi P, Junghans A, Jurado B, Koerner G, Kalantar N, Kanungo R, Kelic-Heil A, Kezzar K, Khan E, Khanzadeev A, Kiselev O, Kogimtzis M, Koerper D, Kraeckmann S, Kroell T, Kruecken R, Krasznahorkay A, Kratz J, Kresan D, Krings T, Krumbholz A, Krupko S, Kulessa R, Kumar S, Kurz N, Kuzmin E, Labiche M, Langanke K, Lazarus I, Le Bleis T, Lederer C, Lemasson A, Lemmon R, Liberati V, Litvinov Y, Loeher B, Lopez Herraiz J, Muenzenberg G, Machado J, Maev E, Mahata K, Mancusi D, Marganiec J, Martinez Perez M, Marusov V, Mengoni D, Million B, Morcelle V, Moreno O, Movsesyan A, Nacher E, Najafi M, Nakamura T, Naqvi F, Nikolski E, Nilsson T, Nociforo C, Nolan P, Novatsky B, Nyman G, Ornelas A, Palit R, Pandit S, Panin V, Paradela C, Parkar V, Paschalis S, Pawlowski P, Perea A, Pereira J, Petrache C, Petri M, Pickstone S, Pietralla N, Pietri S, Pivovarov Y, Potlog P, Prokofiev A, Rastrepina G, Rauscher T, Ribeiro G, Ricciardi M, Richter A, Rigollet C, Riisager K, Rios A, Ritter C, Frutos TR, Rodriguez Vignote J, Roeder M, Romig C, Rossi D, Roussel-Chomaz P, Rout P, Roy S, Soederstroem P, Sarkar MS, Sakuta S, Salsac M, Sampson J, del Rio Saez JS, Sanchez Rosado J, Sanjari S, Sarriguren P, Sauerwein A, Savran D, Scheidenberger C, Scheit H, Schmidt S, Schmitt C, Schnorrenberger L, Schrock P, Schwengner R, Seddon D, Sherrill B, Shrivastava A, Sidorchuk S, Silva J, Simon H, Simpson E, Singh P, Slobodan D, Sohler D, Spieker M, Stach D, Stan E, Stanoiu M, Stepantsov S, Stevenson P, Strieder F, Stuhl L, Suda T, Suemmerer K, Streicher B, Taieb J, Takechi M, Tanihata I, Taylor J, Tengblad O, Ter-Akopian G, Terashima S, Teubig P, Thies R, Thoennessen M, Thomas T, Thornhill J, Thungstrom G, Timar J, Togano Y, Tomohiro U, Tornyi T, Tostevin J, Townsley C, Trautmann W, Trivedi T, Typel S, Uberseder E, Udias J, Uesaka T, Uvarov L, Vajta Z, Velho P, Vikhrov V, Volknandt M, Volkov V, von Neumann-Cose P, von Schmid M, Wagner A, Wamers F, Weick H, Wells D, Westerberg L, Wieland O, Wiescher M, Wimmer C, Wimmer K, Winfield JS, Winkel M, Woods P, Wyss R, Yakorev D, Yavor M, Cardona JZ, Zartova I, Zerguerras T, Zgura I, Zhdanov A, Zhukov M, Zieblinski M, Zilges A, Zuber K (2016) Nuclear astrophysics with radioactive ions at FAIR, NUCLEAR PHYSICS IN ASTROPHYSICS VI (NPA6) 665 IOP PUBLISHING LTD
Maierbeck P, Gernhaeuser R, Kruecken R, Kroell T, Alvarez-Pol H, Aksouh F, Aumann T, Behr K, Benjamim EA, Benlliure J, Bildstein V, Boehmer M, Boretzky K, Borge MJG, Bruenle A, Buerger A, Caamano M, Casarejos E, Chatillon A, Chulkov LV, Cortina-Gil D, Enders J, Eppinger K, Faestermann T, Friese J, Fabbietti L, Gascon M, Geissel H, Gerl J, Gorska M, Hansen PG, Jonson B, Kanungo R, Kiselev O, Kojouharov I, Klimkiewicz A, Kurtukian T, Kurz N, Larsson K, Le Bleis T, Mahata K, Maier L, Nilsson T, Nociforo C, Nyman G, Pascual-Izarra C, Perea A, Perez D, Prochazka A, Rodriguez-Tajes C, Rossi D, Schaffner H, Schrieder G, Schwertel S, Simon H, Sitar B, Stanoiu M, Suemmerer K, Tengblad O, Weick H, Winkler S, Brown BA, Otsuka T, Tostevin J, Rae WDM (2009) Structure of Ti-55 from relativistic one-neutron knockout,PHYSICS LETTERS B 675 (1) pp. 22-27 ELSEVIER SCIENCE BV
Pain SD, Catford WN, Orr NA, Angelique JC, Ashwood NI, Bouchat V, Clarke NM, Curtis N, Freer M, Fulton B, Hanappe F, Labiche M, Lecouey JL, Lemmon R, Mahboub D, Ninane A, Normand G, Soic N, Stuttge L, Timis CN, Tostevin JA, Ziman V, Winfield J (2005) Evidence of a (1d(5/2))(2) component to the Be-12 ground state, Nuclei at the Limits 764 pp. 373-378 AMER INST PHYSICS
Gade A, Janssens RVF, Weisshaar D, Brown BA, Lunderberg E, Albers M, Bader VM, Baugher T, Bazin D, Berryman JS, Campbell CM, Carpenter MP, Chiara CJ, Crawford HL, Cromaz M, Garg U, Hoffman CR, Kondev FG, Langer C, Lauritsen T, Lee IY, Lenzi SM, Matta JT, Nowacki F, Recchia F, Sieja K, Stroberg SR, Tostevin JA, Williams SJ, Wimmer K, Zhu S (2014) Nuclear Structure Towards N=40 Ca60: In-Beam ³-Ray Spectroscopy of Ti58,60,Physical Review Letters 112 112503 APS
Excited states in the neutron-rich N=38, 36 nuclei Ti60 and Ti58 were populated in nucleon-removal reactions from V61 projectiles at 90 MeV/nucleon. The ³-ray transitions from such states in these Ti isotopes were detected with the advanced ³-ray tracking array GRETINA and were corrected event by event for large Doppler shifts (v/c
Kucuk Y, Tostevin JA (2014) Intermediate energy four-body breakup calculations for 22C,Physical Review C: Nuclear Physics 89 (3) 034607
The heaviest particle-bound carbon isotope, C22, is thought to have a Borromean three-body structure. We discuss and compare four-body, i.e. three-body projectile plus target, reaction model calculations of reaction cross sections for such systems that use the fast adiabatic approximation. These methods are efficient and well-suited for quantitative analyses of reactions of neutron-rich nuclei with light target nuclei at secondary beam energies of H300 MeV/nucleon, as are now becoming available. We compare the predictions of the adiabatic model of the reaction both without and when including the additional eikonal approximation that has been used extensively. We show that the reaction cross section calculations have only limited sensitivity to the size and structure of C22 and that the differences arising from use of the eikonal approximation of the reaction mechanism are of a similar magnitude.
Riley LA, Adrich P, Baugher TR, Bazin D, Brown BA, Cook JM, Cottle PD, Diget CA, Gade A, Garland DA, Glasmacher T, Hartl BA, Hosier KE, Kemper KW, Ratkiewicz A, Siwek KP, Stoken DC, Tostevin JA, Weisshaar D (2009) Selectivity of the one-neutron knockout reaction on Cl-45 and the collapse of the N=28 shell closure,PHYSICAL REVIEW C 79 (5) ARTN 051303 AMER PHYSICAL SOC
McDaniel S, Gade A, Janssens RVF, Bazin D, Brown BA, Campbell CM, Carpenter MP, Cook JM, Deacon AN, Dinca D-C, Freeman SJ, Glasmacher T, Hansen PG, Kay BP, Mantica PF, Mueller WF, Terry JR, Tostevin JA, Zhu S (2010) Population of positive-parity states in Sc-53 through one-proton knockout,PHYSICAL REVIEW C 81 (2) ARTN 024301 AMER PHYSICAL SOC
ALKHALILI JS, TOSTEVIN JA, JOHNSON RC (1990) EFFECTS OF SINGLET BREAKUP ON DEUTERON ELASTIC-SCATTERING AT INTERMEDIATE ENERGIES,PHYSICAL REVIEW C 41 (3) pp. R806-R810 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA (2009) One- and two-neutron removal from the neutron-rich carbon isotopes,PHYSICAL REVIEW C 79 (2) ARTN 024616 AMER PHYSICAL SOC
Santos FD, Arriaga A, Eiró AM, Tostevin JA (1985) He4 D-state effects in the H2(d,) 4He reaction,Physical Review C 31 (2) pp. 707-709 American Physical Society
Navin A, Aumann T, Bazin D, Brown BA, Glasmacher T, Hansen PG, Ibbotson RW, Maddalena V, Sherrill BM, Tostevin JA, Yurkon J (1999) Single-particle structure of radioactive beams from one-nucleon knockout reactions,EXPERIMENTAL NUCLEAR PHYSICS IN EUROPE 495 pp. 309-312 AMER INST PHYSICS
Tostevin JA, Gonul B (1995) Extended adiabatic treatments of breakup, Genshikaku Kenkyu 40 pp. 95-104
YAHIRO M, TOSTEVIN J, JOHNSON R (1989) 3-BODY TREATMENT OF THE FINAL-STATE IN THE (3HE,PP) REACTION ON MEDIUM-MASS NUCLEI,PHYS REV LETT 62 (2) pp. 133-136 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA (2011) Two-nucleon correlation effects in knockout reactions from C-12,PHYSICAL REVIEW C 83 (1) ARTN 014605 AMER PHYSICAL SOC
Ridikas D, Mittig W, Tostevin JA (1999) Importance of Coulomb dissociation of the deuteron on nucleon production reactions,PHYS REV C 59 (3) pp. 1555-1559 AMERICAN PHYSICAL SOC
ALKHALILI JS, TOSTEVIN JA, JOHNSON RC (1990) SINGLET CHANNEL COUPLING IN DEUTERON ELASTIC-SCATTERING AT INTERMEDIATE ENERGIES, NUCLEAR PHYSICS A 514 (4) pp. 649-681 ELSEVIER SCIENCE BV
Tostevin JA, Al-Khalili JS (1999) Calculations of reaction cross sections for C-19 at relativistic energies,PHYS REV C 59 (1) pp. R5-R8 AMERICAN PHYSICAL SOC
Gonul B, Tostevin JA (1996) Adiabatic treatment of final states in (p,d*) reactions,PHYS REV C 53 (6) pp. 2949-2957 AMERICAN PHYSICAL SOC
Tostevin JA, Brown, BA, Simpson, EC (2013) Two-proton removal from 44S and the structure of 42Si,Physical Review C: Nuclear Physics 87 (2) 027601 American Physical Society
Newly published 42Si ³-ray spectra and a final-state-inclusive 42Si production cross section value, obtained in a higher-statistics intermediate-energy two-proton removal experiment from 44S, are considered in terms of the final-state-exclusive cross sections computed using proposed shell-model effective interactions for nuclei near N=28. Specifically, we give cross section predictions when using the two nucleon amplitudes of the two-proton overlaps ?42Si(JÀ) | 44S computed using the newly proposed sdpf-mu shell-model Hamiltonian. We show that these partial cross sections or their longitudinal momentum distributions should enable a less-tentative interpretation of the measured gamma-ray spectra and provide a more quantitative assessment of proposed shell-model Hamiltonians in this interesting and challenging region of the chart of nuclides.
Schwertel S, Maierbeck P, Krucken R, Gernhauser R, Kroll T, Alvarez-Pol H, Aksouh F, Aumann T, Behr K, Benjamim EA, Benlliure J, Bildstein V, Bohmer M, Boretzky K, Borge MJG, Brunle A, Burger A, Caamano M, Casarejos E, Chatillon A, Chulkov LV, Cortina-Gil D, Enders J, Eppinger K, Faestermann T, Friese J, Fabbietti L, Gascon M, Geissel H, Gerl J, Gorska M, Hansen PG, Jonson B, Kanungo R, Kiselev O, Kojouharov I, Klimkiewicz A, Kurtukian T, Kurz N, Larsson K, LeBleis T, Mahata K, Maier L, Nilsson T, Nociforo C, Nyman G, Pascual-Izarra C, Perea A, Perez D, Prochazka A, Rodriguez-Tajes C, Rossi D, Schaner H, Schrieder G, Simon H, Sitar B, Stanoiu M, Summerer K, Tengblad O, Weick H, Winkler S, Brown BA, Otsuka T, Tostevin JA, Rae WDM (2012) One-neutron knockout from 51-55Sc, European Physical Journal A: Hadrons and Nuclei 48 (12) 191
Results are presented from a one-neutron knockout experiment at relativistic energies of $ \approx 420 A$ MeV on 51-55Sc using the GSI Fragment Separator as a two-stage magnetic spectrometer and the MINIBALL array for gamma-ray detection. Inclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the contributions corresponding to knockout from the $ \nu p_{1/2}$ , $ \nu p_{3/2}$ , (L = 1 and $ \nu f_{7/2}$ , $ \nu f_{5/2}$ (L = 3 neutron orbitals. The observed L = 1 and L = 3 contributions are compared with theoretical cross-sections using eikonal knockout theory and spectroscopic factors from shell model calculations using the GXPF1A interaction. The measured inclusive knockout cross-sections generally follow the trends expected theoretically and given by the spectroscopic strength predicted from the shell model calculations. However, the deduced L = 1 cross-sections are generally 30-40% higher while the L = 3 contributions are about a factor of two smaller than predicted. This points to a promotion of neutrons from the $ \nu f_{7/2}$ to the $ \nu p_{3/2}$ orbital indicating a weakening of the N = 28 shell gap in these nuclei. While this is not predicted for the phenomenological GXPF1A interaction such a weakening is predicted by recent calculations using realistic low-momentum interactions $ V_{low k}$ obtained by evolving a chiral N3LO nucleon-nucleon potential.
TOSTEVIN JA, JOHNSON RC (1986) ANTISYMMETRIZATION CORRECTIONS TO 3-BODY MODELS OF DEUTERON STRIPPING REACTIONS, PHYSICS LETTERS B 182 (2) pp. 124-128 ELSEVIER SCIENCE BV
Tostevin JA, Rugmai S, Johnson RC (1998) Coulomb dissociation of light nuclei,PHYS REV C 57 (6) pp. 3225-3236 AMERICAN PHYSICAL SOC
Kucuk Y, Tostevin JA (2011) Three-body-model calculations for 22C,Journal of Physics Conference Series 381
There are now several well-studied instances where very neutron-rich light nuclei at or near the neutron drip-line, such as 6He, 11Li and 14Be, have been found to have a Borromean three-body structure. Such systems are modelled effectively as a well-bound core nucleus plus two weakly-bound valence neutrons, where none of the two-body subsystems forms a bound state. It is now known that the heaviest particle-bound carbon isotope, 22C, shares these properties. We discuss a development of four-body reaction model calculations, using the fast adiabatic approximation, that is particularly well-suited for a quantitative analysis of reactions of such neutron-rich nuclei with a target nucleus at beam energies of order 100-300 MeV per nucleon; energies available at new and future radioactive ion beam (RIB) facilities. The 22C projectile wave function is calculated using the 20C core plus two-valence neutron three-body description.
CRESPO R, JOHNSON RC, TOSTEVIN JA, MACKINTOSH RS, COOPER SG (1994) EQUIVALENT LOCAL POTENTIALS TO MULTIPLE-SCATTERING CALCULATIONS OF NUCLEON-NUCLEUS SCATTERING,PHYSICAL REVIEW C 49 (2) pp. 1091-1098 AMER PHYSICAL SOC
Frank N, Baumann T, Bazin D, Brown BA, Brown J, DeYoung PA, Finck JE, Gade A, Hinnefeld J, Howes R, Lecouey J-L, Luther B, Peters WA, Scheit H, Schiller A, Thoennessen M, Tostevin J (2008) Neutron decay spectroscopy of neutron-rich oxygen isotopes, NUCLEAR PHYSICS A 813 (3-4) pp. 199-211 ELSEVIER SCIENCE BV
Banerjee P, Tostevin JA, Thompson IJ (1999) Coulomb break-up of halo nuclei within an adiabatic model,JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 25 (4) pp. 851-853 IOP PUBLISHING LTD
ALKHALILI J, TOSTEVIN J (1994) DYNAMIC POLARIZATION POTENTIAL FOR LI-11 SCATTERING,PHYS REV C 49 (1) pp. 386-390 AMERICAN PHYSICAL SOC
Gade A, Tostevin J (2010) Knockout reactions, Nuclear Physics News 20 (1) pp. 11-16
CRESPO R, JOHNSON RC, TOSTEVIN JA (1990) FULL FOLDING CALCULATIONS FOR PROTON-NUCLEUS ELASTIC-SCATTERING AT INTERMEDIATE ENERGIES,PHYSICAL REVIEW C 41 (5) pp. 2257-2262 AMERICAN PHYSICAL SOC
Zahar M, Belbot M, Kolata JJ, Lamkin K, Morrissey DJ, Sherrill BM, Lewitowicz M, Wuosmaa AH, AlKhalili JS, Tostevin JA, Thompson IJ (1996) Quasielastic scattering of Li-9 on C-12,PHYSICAL REVIEW C 54 (3) pp. 1262-1266 AMERICAN PHYSICAL SOC
Sargeant AJ, Johnson RC, Tostevin JA (1997) Symmetrisation in the semiclassical theory of Coulomb excitation,NUCL PHYS A 624 (3) pp. 299-304 ELSEVIER SCIENCE BV
Brooke JM, Tostevin JA (2000) Correlated scattering corrections to eikonal few-body models,PHYSICAL REVIEW C 62 (6) ARTN 064608 AMERICAN PHYSICAL SOC
Diget CA, Adrich P, Bazin D, Bowen MD, Brown BA, Campbell CM, Cook JM, Gade A, Glasmacher T, Hosier K, McDaniel S, McGlinchery D, Obertelli A, Riley LA, Siwek K, Terry JR, Tostevin JA, Weisshaar D (2008) Structure of excited states in (21)Mg studied in one-neutron knockout,PHYSICAL REVIEW C 77 (6) ARTN 064309 AMER PHYSICAL SOC
Christley JA, Tostevin JA (1999) Reaction cross section calculations for deformed nuclei,PHYSICAL REVIEW C 59 (4) pp. 2309-2312 AMERICAN PHYSICAL SOC
Tostevin JA, Al-Khalili JS (1997) How large are the halos of light nuclei?,Nuclear Physics A 616 (1-2)
We present quantitative reaction cross section calculations for halo nuclei at high energy which retain the essential few-body correlations in such structures. Inclusion of these correlations leads to larger deduced halo radii. For three-body (n+n+core) projectiles, cross section measurements determine the rms hyperradius of the system and, given the core nucleus size, the projectile matter radius. The importance of finite range effects are estimated in the case of the lightest two-neutron-halo system 6He. Outstanding uncertainties are discussed.
Al-Khalili JS, Tostevin JA (1998) Few-body calculations of proton-(6),He-8 scattering,PHYSICAL REVIEW C 57 (4) pp. 1846-1852 AMERICAN PHYSICAL SOC
Wimmer K, Bazin D, Gade A, Tostevin JA, Baugher T, Chajecki Z, Coupland D, Famiano MA, Ghosh TK, Grinyer GF, Howard ME, Kilburn M, Lynch WG, Manning B, Meierbachtol K, Quarterman P, Ratkiewicz A, Sanetullaev A, Showalter RH, Stroberg SR, Tsang MB, Weisshaar D, Winkelbauer J, Winkler R, Youngs M (2014) Elastic breakup cross sections of well-bound nucleons,Physical Review C: Nuclear Physics 90 064615
The Be9(Mg28,Na27) one-proton removal reaction with a large proton separation energy of Sp(Mg28)=16.79 MeV is studied at intermediate beam energy. Coincidences of the bound Na27 residues with protons and other light charged particles are measured. These data are analyzed to determine the percentage contributions to the proton removal cross section from the elastic and inelastic nucleon removal mechanisms. These deduced contributions are compared with the eikonal reaction model predictions and with the previously measured data for reactions involving the removal of more weakly bound protons from lighter nuclei. The role of transitions of the proton between different bound single-particle configurations upon the elastic breakup cross section is also quantified in this well-bound case. The measured and calculated elastic breakup fractions are found to be in good agreement.
Rodriguez-Gallardo M, Arias JM, Gomez-Camacho J, Moro AM, Thompson IJ, Tostevin JA (2009) Four-body continuum-discretized coupled-channels calculations,PHYSICAL REVIEW C 80 (5) ARTN 051601 AMER PHYSICAL SOC
Garcia-Camacho A, Johnson RC, Tostevin JA (2005) Polarization observables and spin-dependent distortion effects in single-nucleon knockout reactions,PHYSICAL REVIEW C 72 (4) ARTN 044603 AMERICAN PHYSICAL SOC
Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Hu Z, Kemper KW, Mueller WF, Olliver H, Perry BC, Riley LA, Roeder BT, Sherrill BM, Terry JR, Tostevin JA, Yurkewicz KL (2005) Spectroscopic factors in exotic nuclei from nucleon-knockout reactions, EUROPEAN PHYSICAL JOURNAL A 25 pp. 251-253 SPRINGER
Crespo R, Johnson RC, Tostevin JA (1996) Mean field calculations of nucleon-nucleus scattering,PHYSICAL REVIEW C 53 (6) pp. 3022-3031 AMERICAN PHYSICAL SOC
Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Honma M, Mizusaki T, Mueller WF, Olliver H, Otsuka T, Riley LA, Terry JR, Tostevin JA, Yurkewicz KL (2005) Nuclear spectroscopy with fast exotic beams, International Symposium on Correlation Dynamics in Nuclei 20 pp. 95-100 IOP PUBLISHING LTD
Grinyer GF, Bazin D, Gade A, Tostevin JA, Adrich P, Bowen MD, Brown BA, Campbell CM, Cook JM, Glasmacher T, McDaniel S, Navratil P, Obertelli A, Quaglioni S, Siwek K, Terry JR, Weisshaar D, Wiringa RB (2011) Knockout Reactions from p-Shell Nuclei: Tests of Ab Initio Structure Models,PHYSICAL REVIEW LETTERS 106 (16) ARTN 162502 AMER PHYSICAL SOC
Enders J, Anthony DW, Aumann T, Bauera A, Baumann T, Bazin D, Blumenfeld Y, Brown BA, Glasmacher T, Hansen PG, Ibbotson RW, Lofy PA, Maddalena V, Miller KL, Nakamura T, Navin A, Pritychenko BV, Sherrill BM, Spears EJ, Steiner M, Tostevin JA, Wagner A, Yurkon J (2001) Study of Si-34,Si-35 and S-37 With single-neutron removal reactions, NUCLEAR PHYSICS A 690 (1-3) pp. 235C-238C ELSEVIER SCIENCE BV
Tostevin JA, Al-Khalili JS (2001) Few-body models of nuclear reactions, In: Pike ER, Sabatier PC (eds.), Scattering 3.1.3
Riley LA, Adrich P, Ahsan N, Baugher TR, Bazin D, Brown BA, Cook JM, Cottle PD, Diget C, Gade A, Glasmacher T, Hosier KE, Kemper KW, Ratkiewicz A, Siwek KP, Tostevin JA, Volya A, Weisshaar D (2012) ³-ray spectroscopy of one-proton knockout from 45Cl,Physical Review C: Nuclear Physics 86 (4) 047301 APS
The role of proton shell effects in the structure of the N=28 isotones 45Cl and 44S has been studied via one-proton knockout from 45Cl. We compare measured ³-ray intensities, inclusive and partial knockout cross sections, and the inclusive momentum distribution of outgoing 44S particles with shell-model and reaction-theory predictions. The strong population in this reaction of the recently identified 41+ state in 44S, identified through its subsequent ³-ray decay energy, makes a compelling case for a JÀ=3/2+ ground state in 45Cl.
Gade A, Adrich P, Bazin D, Bowen MD, Brown BA, Campbell CM, Cook JM, Glasmacher T, Hosier K, McDaniel S, McGlinchery D, Obertelli A, Riley LA, Siwek K, Tostevin JA, Weisshaar D (2007) Inverse-kinematics one-proton pickup with intermediate-energy beams: The (9)Be ((20)Ne,(21)Na+gamma)X reaction,PHYSICAL REVIEW C 76 (6) ARTN 061302 AMER PHYSICAL SOC
Tostevin JA (1999) Theory of nuclear reactions involving halo nuclei, PROCEEDINGS OF THE EUROPEAN CONFERENCE ON ADVANCES IN NUCLEAR PHYSICS AND RELATED AREAS pp. 55-66 GIAHOUDI-GIAPOULI PUBLISHING
Rodriguez-Gallardo M, Arias JM, Gomez-Camacho J, Johnson RC, Moro AM, Thompson IJ, Tostevin JA (2008) Four-body continuum-discretized coupled-channels calculations using a transformed harmonic oscillator basis,PHYSICAL REVIEW C 77 (6) ARTN 064609 AMER PHYSICAL SOC
Wimmer K, Bazin D, Gade A, Tostevin JA, Baugher T, Chajecki Z, Coupland D, Famiano MA, Ghosh TK, Grinyer GF, Hodges R, Howard ME, Kilburn M, Lynch WG, Manning B, Meierbachtol K, Quarterman P, Ratkiewicz A, Sanetullaev A, Simpson EC, Stroberg SR, Tsang MB, Weisshaar D, Winkelbauer J, Winkler R, Youngs M (2012) Correlations in intermediate-energy two-proton removal reactions,Physical Review Letters 109 (20) 202505 American Physical Society
We report final-state-exclusive measurements of the light charged fragments in coincidence with 26Ne residual nuclei following the direct two-proton removal from a neutron-rich 28Mg secondary beam. A Dalitz-plot analysis and comparisons with simulations show that a majority of the triple-coincidence events with two protons display phase-space correlations consistent with the (two-body) kinematics of a spatially correlated pair-removal mechanism. The fraction of such correlated events, 56(12)%, is consistent with the fraction of the calculated cross section, 64%, arising from spin S=0 two-proton configurations in the entrance-channel (shell-model) 28Mg ground state wave function. This result promises access to an additional and more specific probe of the spin and spatial correlations of valence nucleon pairs in exotic nuclei produced as fast secondary beams.
Benstead J, Tostevin J, Escher J, Burke J, Hughes R, Ota S, Casperson R, Thompson I (2016) Calculations of Compound Nucleus Spin-Parity Distributions Populated via the (p,t) Reaction in Support of Surrogate Neutron Capture Measurements,EPJ Web of Conferences 122 EDP Sciences
The surrogate reaction method may be used to determine the cross section for neutron induced reactions not accessible through standard experimental techniques. This is achieved by creating the same compound nucleus as would be expected in the desired reaction, but through a different incident channel, generally a direct transfer reaction. So far, the surrogate technique has been applied with reasonable success to determine the fission cross section for a number of actinides, but has been less successful when applied to other reactions, e.g. neutron capture, due to a ?spin-parity mismatch?. This mismatch, between the spin and parity distributions of the excited levels of the compound nucleus populated in the desired and surrogate channels, leads to differing decay probabilities and hence reduces the validity of using the surrogate method to infer the cross section in the desired channel. A greater theoretical understanding of the expected distribution of levels excited in both the desired and surrogate channels is therefore required in order to attempt to address this mismatch and allow the method to be utilised with greater confidence. Two neutron transfer reactions, e.g. (p,t), which allow the technique to be utilised for isotopes further removed from the line of stability, are the subject of this study. Results are presented for the calculated distribution of compound nucleus states populated in 90Zr, via the 90Zr(p,t)90Zr reaction, and are compared against measured data at an incident proton energy of 28.56 MeV.
Stott JO, Thompson IJ, Tostevin JA (1999) Long-range interactions and artificial poles,J PHYS G NUCL PARTIC 25 (11) pp. 2189-2195 IOP PUBLISHING LTD
Reynolds RR, Cottle PD, Gade A, Bazin D, Campbell CM, Cook JM, Glasmacher T, Hansen PG, Hoagland T, Kemper KW, Mueller WF, Roeder BT, Terry JR, Tostevin JA (2010) Si-25 and S-29 studied via single neutron knockout reactions,PHYSICAL REVIEW C 81 (6) ARTN 067303 AMER PHYSICAL SOC
Kobayashi N, Nakamura T, Tostevin JA, Kondo Y, Aoi N, Baba H, Deguchi S, Gibelin J, Ishihara M, Kawada Y, Kubo T, Motobayashi T, Ohnishi T, Orr NA, Otsu H, Sakurai H, Satou Y, Simpson EC, Sumikama T, Takeda H, Takechi M, Takeuchi S, Tanaka KN, Tanaka N, Togano Y, Yoneda K (2012) One- and two-neutron removal reactions from the most neutron-rich carbon isotopes,Physical Review C: Nuclear Physics 86 (5) 054604
The structure of 19,20,22C has been investigated using high-energy (around 240 MeV/nucleon) one- and two-neutron removal reactions on a carbon target. Measurements were made of the inclusive cross sections and momentum distributions for the charged residues. Narrow momentum distributions were observed for one-neutron removal from 19C and 20C and two-neutron removal from 22C. Two-neutron removal from 20C resulted in a relatively broad momentum distribution. The results are compared with eikonal-model calculations combined with shell-model structure information. The neutron removal cross sections and associated momentum distributions are calculated for transitions to both the particle-bound and particle-unbound final states. The calculations take into account the population of the mass A?1 reaction residues A?1C and, following one-neutron emission after one-neutron removal, the mass A?2 two-neutron removal residues A?2C. The smaller contributions of direct two-neutron removal, that populate the A?2C residues in a single step, are also computed. The data and calculations are shown to be in good overall agreement and consistent with the predicted shell-model ground-state configurations and one-neutron overlaps with low-lying states in 18?21C. These suggest significant ½s1/22 valence neutron configurations in both 20C and 22C. The results for 22C strongly support the picture of 22C as a two-neutron halo nucleus with a dominant ½s1/22 ground-state configuration.
Banerjee P, Tostevin JA, Thompson IJ (1998) Coulomb breakup of two-neutron halo nuclei,PHYS REV C 58 (2) pp. 1337-1340 AMERICAN PHYSICAL SOC
Gade A, Baugher T, Bazin D, Brown BA, Campbell CM, Glasmacher T, Grinyer GF, Honma M, McDaniel S, Meharchand R, Otsuka T, Ratkiewicz A, Tostevin JA, Walsh KA, Weisshaar D (2010) Collectivity at N=50: Ge-82 and Se-84,PHYSICAL REVIEW C 81 (6) ARTN 064326 AMER PHYSICAL SOC
ALKHALILI JS, TOSTEVIN JA, JOHNSON RC, KAWAI M (1988) THE MOMENTUM-DEPENDENT TP TENSOR INTERACTION IN INTERMEDIATE-ENERGY DEUTERON SCATTERING, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 14 (5) pp. L103-L108 IOP PUBLISHING LTD
TOSTEVIN JA, JOHNSON RC (1979) CORRECTIONS TO CONVENTIONAL SUB-COULOMB STRIPPING CALCULATIONS OF TENSOR ANALYZING POWERS, PHYSICS LETTERS B 85 (1) pp. 14-16 ELSEVIER SCIENCE BV
STEPHENSON EJ, CUPPS VR, TOSTEVIN JA, JOHNSON RC, BROWN JD, FOSTER CC, JONES WP, MILLER DW, NANN H, SCHWANDT P (1987) THE EFFECTS OF FAR-SIDE DOMINANCE ON THE J-DEPENDENCE OF THE MEDIUM ENERGY SN-116(D,P)SN-117 REACTION, NUCLEAR PHYSICS A 469 (3) pp. 467-479 ELSEVIER SCIENCE BV
Tostevin JA (2006) Spectroscopy studies using two-nucleon knockout,AIP Conference Proceedings 819 pp. 523-527 American Institute of Physics
Two-proton removal reaction cross sections, from 208Pb at 1 GeV/nucleon, are estimated as an example of the direct population of (high-spin) seniority-2 isomeric states, here in 206Hg. Nucleon removal by both the stripping and diffractive mechanisms is considered. The cross sections in this specific (test) case are significant and can provide direct two-nucleon removal predictions of isomeric ratios
Navin A, Bazin D, Brown BA, Davids B, Gervais G, Glasmacher T, Govaert K, Hansen PG, Hellstrom M, Ibbotson RW (1998) Spectroscopy of radioactive beams from single-nucleon knockout reactions: Application to the sd shell nuclei Al-25 and P-26,P-27,P-28,PHYS REV LETT 81 (23) pp. 5089-5092 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA (2012) Projectile deformation effects on single-nucleon removal reactions,Physical Review C: Nuclear Physics 86 (5) 054603
We discuss intermediate-energy single-nucleon removal reactions from deformed projectile nuclei. The removed nucleon is assumed to originate from a given Nilsson model single-particle state and the inclusive cross sections, to all rotational states of the residual nucleus, are calculated. We investigate the sensitivity of both the stripping cross sections and their momentum distributions to the assumed size of the model space in the Nilsson model calculations and to the shape of the projectile and residue. We show that the cross sections for small deformations follow the decomposition of the Nilsson state in a spherical basis. In the case of large and prolate projectile deformations the removal cross sections from prolate-like Nilsson states, having large values for the asymptotic quantum number nz, are reduced. For oblate-like Nilsson states, with small nz, the removal cross sections are increased. Whatever the deformation, the residue momentum distributions are found to remain robustly characteristic of the orbital angular momentum decomposition of the initial state of the nucleon in the projectile.
Tostevin JA, Al-Khalili JS (1998) Sizes of the He isotopes deduced from proton elastic scattering measurements,ENAM 98: EXOTIC NUCLEI AND ATOMIC MASSES 455 pp. 227-232 AMER INST PHYSICS
Diaz-Torres A, Hinde DJ, Dasgupta M, Milburn GJ, Tostevin JA (2009) Coupled-Channels Approach for Dissipative Quantum Dynamics in Near-Barrier Collisions,FUSION 08 1098 pp. 44-51 AMER INST PHYSICS
A novel quantum dynamical model based on the dissipative quantum dynamics of open quantum systems is presented. It allows the treatment of both deep-inelastic processes and quantum tunneling (fusion) within a fully quantum mechanical coupled-channels approach. Model calculations show the transition from pure state (coherent) to mixed state (decoherent and dissipative) dynamics during a near-barrier nuclear collision. Energy dissipation, due to irreversible decay of giant-dipole excitations of the interacting nuclei, results in hindrance of quantum tunneling
Maddalena V, Aumann T, Bazin D, Brown BA, Caggiano JA, Davids B, Glasmacher T, Hansen PG, Ibbotson RW, Navin A, Pritychenko BV, Scheit H, Sherrill BM, Steiner M, Tostevin JA, Yurkon J (2001) One-nucleon knockout reactions: The test case C-15 and the single-particle structure of C-16,C-17,C-19, NUCLEAR PHYSICS A 682 pp. 332C-338C ELSEVIER SCIENCE BV
CRESPO R, EIRO AM, TOSTEVIN JA (1990) TENSOR INTERACTION EFFECTS IN THE HE-4(H-2,GAMMA)LI-6 CAPTURE REACTION,PHYSICAL REVIEW C 42 (4) pp. 1646-1651 AMERICAN PHYSICAL SOC
Tostevin JA (2007) Nuclear reactions used to probe the structure of nuclei far from stability,ACTA PHYSICA POLONICA B 38 (4) pp. 1195-1203 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Tostevin JA (1999) Core excitation in halo nucleus break-up,JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 25 (4) pp. 735-739 IOP PUBLISHING LTD
Gade A, Bazin D, Bertulani CA, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Hu Z, Kemper KW, Mueller WF, Olliver H, Perry BC, Riley LA, Roeder BT, Sherrill BM, Terry JR, Tostevin JA, Yurkewicz KL (2005) Knockout from Ar-46 : l=3 neutron removal and deviations from eikonal theory,PHYSICAL REVIEW C 71 (5) ARTN 051301 AMERICAN PHYSICAL SOC
CRESPO R, JOHNSON RC, TOSTEVIN JA (1991) MULTIPLE-SCATTERING EFFECTS IN PROTON NUCLEUS ELASTIC-SCATTERING AT INTERMEDIATE ENERGIES,PHYSICAL REVIEW C 44 (5) pp. R1735-R1739 AMERICAN PHYSICAL SOC
CRESPO R, TOSTEVIN JA, JOHNSON RC (1995) SPIN DEPENDENCE OF THE SCATTERING OF PROTONS FROM HALO NUCLEI,PHYSICAL REVIEW C 51 (6) pp. 3283-3289 AMERICAN PHYSICAL SOC
Tostevin JA, Bazin D, Brown BA, Glasmacher T, Hansen PG, Maddalena V, Navin A, Sherrill BM (2002) Single-neutron removal reactions from C-15 and Be-11: Deviations from the eikonal approximation,PHYSICAL REVIEW C 66 (2) ARTN 024607 AMERICAN PHYSICAL SOC
Christley JA, AlKhalili JS, Tostevin JA, Johnson RC (1997) Four-body adiabatic model applied to elastic scattering,NUCL PHYS A 624 (2) pp. 275-292 ELSEVIER SCIENCE BV
Nunes FM, Thompson IJ, Tostevin JA (2002) Core excitation in Be-12,NUCL PHYS A 703 (3-4) pp. 593-602 ELSEVIER SCIENCE BV
Enders J, Anthony DW, Aumann T, Bauer A, Baumann T, Bazin D, Blumenfeld Y, Brown BA, Glasmacher T, Hansen PG, Ibbotson RW, Lofy PA, Maddalena V, Miller KL, Nakamura T, Navin A, Pritychenko BV, Sherrill BM, Spears EJ, Steiner M, Tostevin JA, Wagner A, Yurkon J (2001) Study of 34,35Si and 37S with single-neutron removal reactions, Nuclear Physics A 690 (1-3)
Preliminary results of one-neutron removal reactions on the nuclei 34,35Si and 37S at the intersection of the 1s0d and 1p0f neutron shells are reported. Momentum distributions of the projectile residues have been measured at the National Superconducting Cyclotron Laboratory at Michigan State University. The populated final states in the neutron removal reactions could be resolved by measuring the ³ rays from the de-excitation of bound states using a position-sensitive NaI(T1) array. Partial cross sections to specific final states have been deduced. A comparison of the cross sections in the reactions (35Si,34Si) and (37S,36S) shows differences that point to the influence of intruder configurations in the vicinity of 34Si.
AlKhalili JS, Tostevin JA, Brooke JM (1997) Beyond the eikonal model for few-body systems,PHYS REV C 55 (3) pp. R1018-R1022 AMERICAN PHYSICAL SOC
THOMPSON IJ, ALKHALILI JS, TOSTEVIN JA, BANG JM (1993) QUASI-ELASTIC SCATTERING OF LI-11 USING REALISTIC 3-BODY WAVE-FUNCTIONS,PHYSICAL REVIEW C 47 (4) pp. R1364-R1368 AMERICAN PHYSICAL SOC
Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Hu Z, Kemper KW, Mueller WF, Olliver H, Perry BC, Riley LA, Roeder BT, Sherrill BM, Terry JR, Tostevin JA, Yurkewicz KL (2004) One-neutron knockout reactions on proton-rich nuclei with N=16,PHYSICAL REVIEW C 69 (3) ARTN 034311 AMERICAN PHYSICAL SOC
Santiago-Gonzalez D, Wiedenhoever I, Abramkina V, Avila ML, Baugher T, Bazin D, Brown BA, Cottle PD, Gade A, Glasmacher T, Kemper KW, McDaniel S, Rojas A, Ratkiewicz A, Meharchand R, Simpson EC, Tostevin JA, Volya A, Weisshaar D (2011) Triple configuration coexistence in S-44,PHYSICAL REVIEW C 83 (6) ARTN 061305 AMER PHYSICAL SOC
Margerin V, Lotay G, Woods PJ, Aliotta M, Christian G, Davids B, Davinson T, Doherty DT, Fallis J, Howell D, Kirsebom OS, Mountford DJ, Rojas A, Ruiz C, Tostevin JA (2015) Inverse Kinematic Study of the Al-26g(d,p)Al-27 Reaction and Implications for Destruction of Al-26 in Wolf-Rayet and Asymptotic Giant Branch Stars,PHYSICAL REVIEW LETTERS 115 (6) ARTN 062701 AMER PHYSICAL SOC
BOWSHER J, CLEGG T, KARWOWSKI H, LUDWIG E, THOMPSON W, TOSTEVIN J (1992) EFFECTS OF LI-6 EXCITATION IN ZN-64(D-], LI-6)NI-60 AT LOW ENERGIES,PHYS REV C 45 (6) pp. 2824-2835 AMERICAN PHYSICAL SOC
Timofeyuk NK, Blokhintsev LD, Tostevin JA (2003) Pre-asymptotic behavior of single-particle overlap integrals of non-Borromean two-neutron halos,PHYSICAL REVIEW C 68 (2) ARTN 021601 AMERICAN PHYSICAL SOC
LOPES M, TOSTEVIN J, JOHNSON R (1983) ELECTRIC POLARIZABILITY OF THE DEUTERON AND THE NUCLEON-NUCLEON INTERACTION,PHYS REV C 28 (4) pp. 1779-1782 AMERICAN PHYSICAL SOC
Terry JR, Bazin D, Brown BA, Campbell CM, Church JA, Cook JM, Davies AD, Dinca D-C, Enders J, Gade A, Glasmacher T, Hansen PG, Lecouey JL, Otsuka T, Pritychenko B, Sherrill BM, Tostevin JA, Utsuno Y, Yoneda K, Zwahlen H (2006) Direct evidence for the onset of intruder configurations in neutron-rich Ne isotopes,PHYSICS LETTERS B 640 (3) pp. 86-90 ELSEVIER SCIENCE BV
Stroberg SR, Gade A, Tostevin JA, Bader VM, Baugher T, Bazin D, Berryman JR, Brown BA, Campbell CM, Kemper KW, Langer C, Lunderberg E, Lemasson A, Noji S, Otsuka T, Reccia F, Walz C, Weisshaar D, Williams S (2015) Neutron single-particle strength in silicon isotopes: Constraining the driving forces of shell evolution,Physical Review C: Nuclear Physics 91 (4) 041302 American Physical Society
Shell evolution is studied in the neutron-rich silicon isotopes Si36,38,40 using neutron single-particle strengths deduced from one-neutron knockout reactions. Configurations involving neutron excitations across the N=20 and N=28 shell gaps are quantified experimentally in these rare isotopes. Comparisons with shell model calculations show that the tensor force, understood to drive the collective behavior in Si42 with N=28, is already important in determining the structure of Si40 with N=26. New data relating to cross-shell excitations provide the first quantitative support for repulsive contributions to the cross-shell T=1 interaction arising from three-nucleon forces.
Jones KL, Ahn S, Allmond JM, Ayres A, Bardayan DW, Baugher T, Bazin D, Berryman JS, Bey A, Bingham C, Cartegni L, Cerizza G, Chae KY, Cizewski JA, Gade A, Galindo-Uribarri A, Garcia-Ruiz RF, Grzywacz R, Howard ME, Kozub RL, Liang JF, Manning B, Matoa M, McDaniel S, Miller D, Nesaraja CD, O'Malley PD, Padgett S, Padilla-Rodal E, Pain SD, Pittman ST, Radford DC, Ratkiewicz A, Schmitt KT, Shore A, Smith MS, Stracener DW, Stroberg SR, Tostevin J, Varner RL, Weisshaar D, Wimmer K, Winkler R (2015) Recent Direct Reaction Experimental Studies with Radioactive Tin Beams,Acta Physica Polonica, Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory 46 (3) pp. 537-546
Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z = 50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, N = 82, and neutron-deficient, N = 50, regions. Here, we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in 131Sn from across the N = 82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn. In both cases, measurements of ³ rays in coincidence with charged particles proved to be invaluable.
Riley LA, Adrich P, Baugher TR, Bazin D, Brown BA, Cook JM, Cottle PD, Diget CA, Gade A, Garland DA, Glasmacher T, Hosier KE, Kemper KW, Otsuka T, Rae WDM, Ratkiewicz A, Siwek KP, Tostevin JA, Utsuno Y, Weisshaar D (2008) d(5/2) proton hole strength in neutron-rich (43)P: Shell structure and nuclear shapes near N=28,PHYSICAL REVIEW C 78 (1) ARTN 011303 AMER PHYSICAL SOC
Gade A, Tostevin JA, Baugher T, Bazin D, Brown BA, Campbell CM, Glasmacher T, Grinyer GF, McDaniel S, Meierbachtol K, Ratkiewicz A, Stroberg SR, Walsh KA, Weisshaar D, Winkler R (2011) Inverse-kinematics one-neutron pickup with fast rare-isotope beams,PHYSICAL REVIEW C 83 (5) ARTN 054324 AMER PHYSICAL SOC
Tostevin JA (2001) Single-nucleon knockout reactions at fragmentation beam energies,NUCLEAR PHYSICS A 682 pp. 320C-331C ELSEVIER SCIENCE BV
Peters WA, Baumann T, Brown BA, Brown J, DeYoung PA, Finck JE, Frank N, Jones KL, Lecouey J-L, Luther B, Peaslee GF, Rogers WF, Schiller A, Thoennessen M, Tostevin JA, Yoneda K (2011) Neutron knockout of Be-12 populating neutron-unbound states in Be-11,PHYSICAL REVIEW C 83 (5) ARTN 057304 AMER PHYSICAL SOC
Cerizza G, Ayres A, Jones KL, Grzywacz R, Bey A, Bingham C, Cartegni L, Miller D, Padgett S, Baugher T, Bazin D, Berryman JS, Gade A, McDaniel S, Ratkiewicz A, Shore A, Stroberg SR, Weisshaar D, Wimmer K, Winkler R, Pain SD, Chae KY, Cizewski JA, Tostevin JA, Howard ME (2016) Structure of 107Sn studied through single-neutron knockout reactions,Physical Review C: Nuclear Physics 93 (2) 021601
The neutron-deficient nucleus Sn 107 has been studied by using the one-neutron knockout reaction. By measuring the decay ³ rays and momentum distributions of reaction residues, the spins of the ground, 5/2 + , and first-excited, 7/2 + , states of Sn 107 have been assigned by comparisons to eikonal-model reaction calculations. Limits on the inclusive and exclusive cross sections have been measured and transitions due to neutron removals from below the N=50 closed shell have been observed. New excited states up to 5.5 MeV in Sn 107 have been identified.
Grinyer GF, Bazin D, Gade A, Tostevin JA, Adrich P, Bowen MD, Brown BA, Campbell CM, Cook JM, Glasmacher T, McDaniel S, Obertelli A, Siwek K, Terry JR, Weisshaar D, Wiringa RB (2012) Systematic study of p-shell nuclei via single nucleon knockout reactions,Physical Review C: Nuclear Physics 86 (2) 024315 American Physical Society
A systematic investigation of the inclusive cross sections for single-nucleon knockout reactions from p-shell nuclei has been performed. A total of seven reactions were studied for projectiles with masses between A = 7 and 10, having a wide range of nucleon separation energies. Results were obtained for a range of incident beam energies and targets. These differences were found to have a minimal impact on the deduced cross sections. Experimental results were compared to theoretical predictions based on variational Monte Carlo (VMC) nuclear structure calculations, whose radial overlap functions and neutron and proton densities were included in the reaction description. These results are compared with the conventional model, developed for heavier nuclei, that uses shell-model and Hartree-Fock structure inputs. The VMC-based calculations agreed with the experimental data for several reactions where deeply bound nucleons are removed but does not describe some of the more weakly bound nucleon removal cases with comparable accuracy.
Navin A, Anthony DW, Aumann T, Baumann T, Bazin D, Blumenfeld Y, Brown BA, Glasmacher T, Hansen PG, Ibbotson RW, Lofy PA, Maddalena V, Miller K, Nakamura T, Pritychenko BV, Sherrill BM, Spears E, Steiner M, Tostevin JA, Yurkon J, Wagner A (2000) Direct evidence for the breakdown of the N=8 shell closure in Be-12,PHYS REV LETT 85 (2) pp. 266-269 AMERICAN PHYSICAL SOC
Terry JR, Brown BA, Campbell CM, Cook JM, Davies AD, Dinca D-C, Gade A, Glasmacher T, Hansen PG, Sherrill BM, Zwahlen H, Bazin D, Yoneda K, Tostevin JA, Otsuka T, Utsuno Y, Pritychenko B (2008) Single-neutron knockout from intermediate energy beams of Mg-30,Mg-32: Mapping the transition into the "island of inversion",PHYSICAL REVIEW C 77 (1) ARTN 014316 AMER PHYSICAL SOC
Pain SD, Catford WN, Orr NA, Angélique JC, Ashwood NI, Bouchat V, Clarke NM, Curtis N, Freer M, Fulton BR, Hanappe F, Labiche M, Lecouey JL, Lemmon RC, Mahboub D, Ninane A, Normand G, Soi? N, Stuttge L, Timis CN, Tostevin JA, Winfield JS, Ziman V (2006) Structure of 12Be: intruder d-wave strength at N=8.,Phys Rev Lett 96 (3)
The breaking of the N=8 shell-model magic number in the 12Be ground state has been determined to include significant occupancy of the intruder d-wave orbital. This is in marked contrast with all other N=8 isotones, both more and less exotic than 12Be. The occupancies of the [FORMULA: SEE TEXT]orbital and the [FORMULA: SEE TEXT], intruder orbital were deduced from a measurement of neutron removal from a high-energy 12Be beam leading to bound and unbound states in 11Be.
Aumann T, Navin A, Balamuth DP, Bazin D, Blank B, Brown BA, Bush JE, Caggiano JA, Davids B, Glasmacher T, Guimaraes V, Hansen PG, Ibbotson RW, Karnes D, Kolata JJ, Maddalena V, Pritychenko B, Scheit H, Sherrill BM, Tostevin JA (2000) One-neutron knockout from individual single-particle states of Be-11,PHYSICAL REVIEW LETTERS 84 (1) pp. 35-38 AMERICAN PHYSICAL SOC
Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Honma M, Mizusaki T, Mueller WF, Olliver H, Otsuka T, Riley LA, Terry JR, Tostevin JA, Yurkewicz KL (2005) Nuclear spectroscopy with fast exotic beams, ACTA PHYSICA POLONICA B 36 (4) pp. 1227-1233 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Rodríguez-Gallardo M, Arias JM, Gómez-Camacho J, Moro AM, Thompson J, Tostevin JA (2010) Four-body continuum-discretized coupled-channels calculations: Application to 6He+64Zn at 13.6 MeV,AIP Conference Proceedings 1231 pp. 235-236 American Institute of Physics
The recently developed four-body continuum-discretized coupled-channels (CDCC) method, making use of the binning procedure [1], is applied to the reaction 6He+64Zn at 13.6 MeV (around the Coulomb barrier). Excellent agreement with available elastic data [2] is found.
Warner RE, Becchetti FD, Brown JA, Galonsky A, Kelley JH, Nadasen A, Ronningen RM, Tostevin JA, Winfield JS, Zecher P (2004) Proton removal from B-8, C-9, and C-12 on Si at 20-70 MeV/nucleon,PHYSICAL REVIEW C 69 (2) ARTN 024612 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA, Podolyak Z, Regan PH, Steer SJ (2010) Differential isomeric ratios following two-proton knockout from Pb-208,PHYSICAL REVIEW C 82 (3) ARTN 037602 AMER PHYSICAL SOC
Riley LA, Adrich P, Baugher TR, Bazin D, Brown BA, Cook JM, Cottle PD, Diget CA, Gade A, Garland DA, Glasmacher T, Hosier KE, Kemper KW, Ratkiewicz A, Siwek KP, Tostevin JA, Weisshaar D (2009) Rotational and neutron-hole states in S-43 via the neutron knockout and fragmentation reactions,PHYSICAL REVIEW C 80 (3) ARTN 037305 AMER PHYSICAL SOC
Hansen PG, Tostevin JA (2003) Direct reactions with exotic nuclei, ANNUAL REVIEW OF NUCLEAR AND PARTICLE SCIENCE 53 pp. 219-261 ANNUAL REVIEWS
Thompson IJ, Tostevin JA, Nunes FM (2001) Multistep Coulomb and nuclear breakup of one-nucleon halo nuclei,NUCLEAR PHYSICS A 690 (1-3) pp. 294C-297C ELSEVIER SCIENCE BV
Coulomb dissociation of one neutron halo nuclei ?IBe and 15,1QC has been studied at energies
around 70A MeV by kinematically complete measurements of breakup particles at
RIKEN. The experiment of l1Be breakup on a Pb target aims at studying the characteristic
features of low-lying El strength. In particular the effects of higher order excitation
and nuclear contribution have been closely studies by using the impact parameter analysis.
We have found that these contributions are very small, and the selection of the large
impact parameter is useful to extract the spectroscopic information of the halo ground
state. We have then successfully applied this analysis method to l?C and ?C, where we
have extracted the spectroscopic factor for the s-wave halo configuration. We also show
preliminary results on the breakup of ?Be on a carbon target in order to study the nuclear
breakup mechanism and low-lying discrete states of the halo nucleus.
Kobayashi N, Nakamura T, Kondo Y, Tostevin JA, Utsuno Y, Aoi N, Baba H, Bartelemy R, Famiano MA, Fukuda N, Inabe N, Ishihara M, Kunungo R, Kim, Kim S, Kubo T, Lee GS, Lee HS, Matsushita M, Motobayashi T, Ohnishi T, Orr NA, Otsu H, Otsuka T, Sako T, Sakurai H, Satou Y, Sumikama T, Takeda H, Takeuchi S, Tanaka R, Togano Y, Yoneda K (2014) Observation of a p-Wave One-Neutron Halo Configuration in 37Mg,Physical Review Letters 112 242501
Cross sections of 1n-removal reactions from the neutron-rich nucleus Mg37 on C and Pb targets and the parallel momentum distributions of the Mg37 residues from the C target have been measured at 240 MeV/nucleon. A combined analysis of these distinct nuclear- and Coulomb-dominated reaction data shows that the Mg37 ground state has a small 1n separation energy of 0.22+0.12?0.09 MeV and an appreciable p-wave neutron single-particle strength. These results confirm that Mg37 lies near the edge of the ?island of inversion? and has a sizable p-wave neutron halo component, the heaviest such system identified to date.
Tostevin JA, Johnson RC, Al-Khalili JS (1998) Manifestation of halo size in scattering and reactions,NUCLEAR PHYSICS A 630 (1-2) pp. 340C-351C ELSEVIER SCIENCE BV
Shane R, Charity RJ, Sobotka LG, Bazin D, Brown BA, Gade A, Grinyer GF, McDaniel S, Ratkiewicz A, Weisshaar D, Bonaccorso A, Tostevin JA (2012) Proton and neutron knockout from 36Ca,Physical Review C: Nuclear Physics 85 (6) 064612 American Physical Society
The cross sections for single-nucleon knockout from Ca-36 on a Be-9 target at 70 MeV/nucleon were measured to be sigma(exp)(-p) = 51.1 +/- 2.6 mb for proton knockout and sigma(exp)(-n) = 5.03 +/- 0.46 mb for neutron knockout. The spectroscopic factors and orbital angular momenta of the neutrons and protons removed from Ca-36, leading to bound A = 35 residues, were deduced by comparison of the experimental cross sections and longitudinal- momentum distributions to those calculated in an eikonal reaction theory, and found to be S(p, 1d(3/2)) = 0.79 +/- 0.04 and S(n, 2s(1/2)) = 0.23 +/- 0.02 (relative to independent-particle-model values and only including experimental contributions to the uncertainties). As found in previous knockout studies, the spectroscopic factor deduced for the deeply bound neutron was significantly reduced relative to shell-model calculations, a result at variance with dispersive optical model (DOM) extrapolations, which suggest a spectroscopic factor closer to 60% of the independent-particle-model value.
Tostevin JA, Brooke JM, Mortimer J, Thompson IJ (2002) Eikonal and coupled-channels reaction methods applied to studies of weakly bound nuclei,PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT (146) pp. 338-347 PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE
Bazin D, Charity RJ, de Souza RT, Famiano MA, Gade A, Henzl V, Henzlova D, Hudan S, Lee J, Lukyanov S, Lynch WG, McDaniel S, Mocko M, Obertelli A, Rogers AM, Sobotka LG, Terry JR, Tostevin JA, Tsang MB, Wallace MS (2009) Mechanisms in Knockout Reactions,PHYSICAL REVIEW LETTERS 102 (23) ARTN 232501 AMER PHYSICAL SOC
Tostevin JA, Rugmai S, Johnson RC, Okamura H, Ishida S, Sakamoto N, Otsu H, Uesaka T, Wakasa T, Sakai H (1998) Coulomb breakup of light composite nuclei,PHYS LETT B 424 (3-4) pp. 219-225 ELSEVIER SCIENCE BV
Kolos K, Miller D, Grzywacz R, Iwasaki H, Al-Shudifat M, Bazin D, Bingham CR, Braunroth T, Cerizza G, Gade A, Lemasson A, Liddick SN, Madurga M, Morse C, Portillo M, Rajabali MM, Recchia F, Riedinger LL, Voss P, Walters WB, Weisshaar D, Whitmore K, Wimmer K, Tostevin JA (2016) Direct Lifetime Measurements of the Excited States in Ni72,Physical Review Letters 116 122502 American Physical Society
The lifetimes of the first excited 2+ and 4+ states in Ni72 were measured at the National Superconducting Cyclotron Laboratory with the recoil-distance Doppler-shift method, a model-independent probe to obtain the reduced transition probability. Excited states in Ni72 were populated by the one-proton knockout reaction of an intermediate energy Cu73 beam. ³-ray-recoil coincidences were detected with the ³-ray tracking array GRETINA and the S800 spectrograph. Our results provide evidence of enhanced transition probability B(E2;2+’0+) as compared to Ni68, but do not confirm the trend of large B(E2) values reported in the neighboring isotope Ni70 obtained from Coulomb excitation measurement. The results are compared to shell model calculations. The lifetime obtained for the excited 4+1 state is consistent with models showing decay of a seniority ½=4, 4+ state, which is consistent with the disappearance of the 8+ isomer in Ni72.
Simpson EC, Tostevin JA, Bazin D, Gade A (2009) Longitudinal momentum distributions of the reaction residues following fast two-nucleon knockout reactions,PHYSICAL REVIEW C 79 (6) ARTN 064621 AMER PHYSICAL SOC
Recchia F, Weisshaar D, Gade A, Tostevin JA, Janssens RVF, Albers M, Bader VM, Baugher T, Bazin D, Berryman JS, Brown BA, Campbell CM, Carpenter MP, Chen J, Chiara CJ, Crawford HL, Hoffman CR, Kondev FG, Korichi A, Langer C, Lauritsen T, Liddick SN, Lunderberg E, Noji S, Prokop C, Stroberg SR, Suchyta S, Wimmer K, Zhu S (2016) Neutron single-particle strengths at N = 40, 42: Neutron knockout from 68,70Ni ground and isomeric states,Physical Review C: Nuclear Physics 94 (5) 054324 American Physical Society
The distribution of single-particle strength in 67,69Ni was characterized with one-neutron knockout
reactions from intermediate-energy 68,70Ni secondary beams, selectively populating neutron-hole
configurations at N = 39 and 41, respectively. The spectroscopic strengths deduced from the
measured partial cross sections to the individual final states, as tagged by their ³-ray decays, are
used to identify and quantify neutron configurations in the wave functions. While 69Ni compares well
to shell-model predictions, the results for 67Ni challenge the validity of current effective shell-model
Hamiltonians by revealing discrepancies that cannot be explained so far. These results suggest
that our understanding of the low-lying states in the neutron-rich, semi-magic Ni isotopes may be
incomplete and requires further investigation on both the experimental and theoretical sides.
Simpson EC, Tostevin JA, Bazin D, Brown BA, Gade A (2009) Two-Nucleon Knockout Spectroscopy at the Limits of Nuclear Stability,PHYSICAL REVIEW LETTERS 102 (13) ARTN 132502 AMER PHYSICAL SOC
CRESPO R, TOSTEVIN JA (1990) TREATMENT OF THE COULOMB INTERACTION IN MOMENTUM SPACE CALCULATIONS OF PROTON ELASTIC-SCATTERING,PHYSICAL REVIEW C 41 (6) pp. 2615-2619 AMERICAN PHYSICAL SOC
CRESPO R, JOHNSON RC, TOSTEVIN JA (1993) BINDING EFFECTS IN PROTON-NUCLEUS ELASTIC-SCATTERING,PHYSICAL REVIEW C 48 (1) pp. 351-356 AMERICAN PHYSICAL SOC
Tarutina T, Thompson IJ, Tostevin JA (2004) Study of Be-14 with core excitation,NUCL PHYS A 733 (1-2) pp. 53-66 ELSEVIER SCIENCE BV
Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Gade A, Glasmacher T, Hansen PG, Mueller WF, Olliver H, Perry BC, Sherrill BM, Terry JR, Tostevin JA (2004) Two-proton knockout on neutron-rich nuclei,NUCLEAR PHYSICS A 746 pp. 173C-177C ELSEVIER SCIENCE BV
Adrich P, Amthor AM, Bazin D, Bowen MD, Brown BA, Campbell CM, Cook JM, Gade A, Galaviz D, Glasmacher T, McDaniel S, Miller D, Obertelli A, Shimbara Y, Siwek KP, Tostevin JA, Weisshaar D (2008) In-beam gamma-ray spectroscopy and inclusive two-proton knockout cross section measurements at N approximate to 40,PHYSICAL REVIEW C 77 (5) ARTN 054306 AMER PHYSICAL SOC
Lee J, Tostevin JA, Brown BA, Delaunay F, Lynch WG, Saelim MJ, Tsang MB (2006) Reduced neutron spectroscopic factors when using potential geometries constrained by Hartree-Fock calculations,PHYSICAL REVIEW C 73 (4) ARTN 044608 AMERICAN PHYSICAL SOC
Gade A, Janssens RVF, Bazin D, Broda R, Brown BA, Campbell CM, Carpenter MP, Cook JM, Deacon AN, Dinca D-C, Fornal B, Freeman SJ, Glasmacher T, Hansen PG, Kay BP, Mantica PF, Mueller WF, Terry JR, Tostevin JA, Zhu S (2006) Cross-shell excitation in two-proton knockout: Structure of Ca-52,PHYSICAL REVIEW C 74 (2) ARTN 021302 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA, Podolyak Z, Regan PH, Steer SJ (2009) Population of low-seniority isomeric states of Hg-206 by two-proton knockout reactions at relativistic energies,PHYSICAL REVIEW C 80 (6) ARTN 064608 AMER PHYSICAL SOC
Mutschler A, Sorlin O, Lemasson A, Bazin D, Borcea C, Borcea R, Gade A, Iwasaki H, Khan E, Lepailleur A, Recchia F, Roger T, Rotaru F, Stanoiu M, Stroberg SR, Tostevin JA, Vandebrouck M, Weisshaar D, Wimmer K (2016) Spectroscopy of P-35 using the one-proton knockout reaction,PHYSICAL REVIEW C 93 (3) ARTN 034333 AMER PHYSICAL SOC
STEPHENSON EJ, TOSTEVIN JA (1991) MODIFICATIONS OF THE EFFECTIVE ISOVECTOR INTERACTION FROM STUDIES OF ((P)RIGHT-ARROW,(P)RIGHT-ARROW') POLARIZATION TRANSFER, SPIN AND ISOSPIN IN NUCLEAR INTERACTIONS pp. 281-286 PLENUM PRESS DIV PLENUM PUBLISHING CORP
Tostevin JA (1986) H2(d,)He4 reaction and the He4 D state,Physical Review C 34 (4) pp. 1497-1500 The American Physical Society
Fridmann J, Wiedenhover I, Gade A, Baby LT, Bazin D, Brown BA, Campbell CM, Cook JM, Cottle PD, Diffenderfer E, Dinca D-C, Glasmacher T, Hansen PG, Kemper KW, Lecouey JL, Mueller WF, Rodriguez-Vieitez E, Terry JR, Tostevin JA, Yoneda K, Zwahlen H (2006) Shell structure at N=28 near the dripline: Spectroscopy of Si-42, P-43, and S-44,PHYSICAL REVIEW C 74 (3) ARTN 034313 AMERICAN PHYSICAL SOC
TOSTEVIN JA, JOHNSON RC (1983) ON THE SPIN-DEPENDENCE OF TRANSFER CHANNEL COUPLING IN SUB-COULOMB DEUTERON SCATTERING, PHYSICS LETTERS B 124 (3-4) pp. 135-138 ELSEVIER SCIENCE BV
Gade A, Adrich P, Bazin D, Bowen MD, Brown BA, Campbell CM, Cook JM, Ettenauer S, Glasmacher T, Kemper KW, McDaniel S, Obertelli A, Otsuka T, Ratkiewicz A, Siwek K, Terry JR, Tostevin JA, Utsuno Y, Weisshaar D (2007) Spectroscopy of Mg-36: Interplay of normal and intruder configurations at the neutron-rich boundary of the "Island of Inversion",PHYSICAL REVIEW LETTERS 99 (7) ARTN 072502 AMER PHYSICAL SOC
Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Hu Z, Kemper KW, Mueller WF, Olliver H, Perry BC, Riley LA, Roeder BT, Sherrill BM, Terry JR, Tostevin JA, Yurkewicz KL (2004) Reduced occupancy of the deeply bound 0d(5/2) neutron state in Ar-32,PHYSICAL REVIEW LETTERS 93 (4) ARTN 042501 AMERICAN PHYSICAL SOC
Milne SA, Bentley MA, Simpson EC, Dodsworth P, Baugher T, Bazin D, Berryman JS, Bruce AM, Davies PJ, Diget CA, Gade A, Henry TW, Iwasaki H, Lemasson A, Lenzi SM, McDaniel S, Napoli DR, Nichols AJ, Ratkiewicz A, Scruton L, Stroberg SR, Tostevin JA, Weisshaar D, Wimmer K, Winkler R (2016) Mirrored one-nucleon knockout reactions to the T-z = +/- 3/2 A=53 mirror nuclei,PHYSICAL REVIEW C 93 (2) ARTN 024318 AMER PHYSICAL SOC
Simpson EC, Tostevin JA (2010) Correlations probed in direct two-nucleon removal reactions,PHYSICAL REVIEW C 82 (4) ARTN 044616 AMER PHYSICAL SOC
Tostevin JA, Podolyak G, Brown BA, Hansen PG (2004) Correlated two-nucleon stripping reactions,PHYSICAL REVIEW C 70 (6) ARTN 064602 AMER PHYSICAL SOC
Yurkewicz KL, Bazin D, Brown BA, Enders J, Gade A, Glasmacher T, Hansen PG, Maddalena V, Navin A, Sherrill BM, Tostevin JA (2006) One-neutron knockout from Ni-57,PHYSICAL REVIEW C 74 (2) ARTN 024304 AMERICAN PHYSICAL SOC
Otsuki K, Truran J, Wiescher M, Gorres J, Mathews G, Frekers D, Mengoni A, Bartlett A, Tostevin J (2006) Origin of the main r-process elements,AIP Conference Proceedings 847 pp. 227-232 American Institute of Physics
The r-process is supposed to be a primary process which assembles heavy nuclei from a photo-dissociated nucleon gas. Hence, the reaction flow through light elements can be important as a constraint on the conditions for the r-process. We have studied the impact of di-neutron capture and the neutron-capture of light (Z
ABUKAMAR S, IGARASHI M, JOHNSON RC, TOSTEVIN JA (1988) THE H-2(D,N)HE-3 REACTION AT VERY LOW ENERGIES, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 14 (1) pp. L1-L6 IOP PUBLISHING LTD
Stroberg SR, Gade A, Tostevin JA, Bader VM, Baugher T, Bazin D, Berryman JS, Brown BA, Campbell CM, Kemper KW, Langer C, Lunderberg E, Lemasson A, Noji S, Recchia F, Walz C, Weisshaar D, Williams SJ (2014) Single-particle structure of silicon isotopes approaching 42Si,Physical Review C: Nuclear Physics 90 034301
The structure of the neutron-rich silicon isotopes Si36,38,40 was studied by one-neutron and one-proton knockout reactions at intermediate beam energies. We construct level schemes for the knockout residues Si35,37,39 and Al35,37,39 and compare knockout cross sections to the predictions of an eikonal model in conjunction with large-scale shell-model calculations. The agreement of these calculations with the present experiment lends support to the microscopic explanation of the enhanced collectivity in the region of Si42. We also present an empirical method for reproducing the observed low-momentum tails in the parallel momentum distributions of knockout residues.
TOSTEVIN JA (1987) THE ORIGIN OF THE SPIN-DEPENDENCE OF LOW-ENERGY DEUTERON SCATTERING, NUCLEAR PHYSICS A 466 (2) pp. 349-370 ELSEVIER SCIENCE BV
Pain SD, Catford WN, Orr NA, Angelique JC, Ashwood NI, Bouchat V, Clarke NM, Curtis N, Freer M, Fulton BR, Hanappe F, Labiche M, Lecouey JL, Lemmon RC, Mahboub D, Ninane A, Normand G, Soic N, Stuttge L, Timis CN, Tostevin JA, Winfield JS, Ziman V (2005) Experimental evidence of a v(1d(5/2))(2) component to the Be-12 ground state, EUROPEAN PHYSICAL JOURNAL A 25 pp. 349-351 SPRINGER
Nishioka H, Tostevin JA, Johnson RC (1983) Deformation effects in aligned 6Li scattering, Physics Letters B 124 (1-2) pp. 17-20
A second rank tensor potential for 6Li scattering is obtained within the framework of a single folding model by assuming an ± + d cluster structure for 6Li. The intercluster wavefunction contains D-state and S-state components with amplitudes chosen to reproduce the experimental value of the 6Li Q-moment. Calculations are made for 6Li + 58Ni elastic scattering at Ecm = 18.1 MeV. The puzzling behaviour of the measured tensor analysing power (TT20) is reproduced. © 1983.
Tostevin JA, Al-Khalili JS, Brooke JM, Christley JA (1998) Sizes and interactions of halo nuclei,JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 24 (8) pp. 1589-1597 IOP PUBLISHING LTD
Tostevin JA (2011) Direct Reaction Probes of Single-Particle States and Correlations,Progress of Theoretical Physics Supplement 196 pp. 275-282
The most exotic neutron-proton asymmetric nuclei are produced most efficiently in high-energy fragmentation reactions. These exotic nuclei are produced as fast secondary beams with energies of order 100 MeV per nucleon or greater, and hence v/c > 0.3, often with relatively low intensities. For such beams one can exploit both the detection efficiency and the cross sections for fast one- and two-nucleon removal reactions. The reaction dynamics of these channels is relatively simple due to the fast (sudden), surface grazing, and forward travelling (eikonal) nature of the reaction mechanism. More recent work now interfaces these sudden, eikonal reaction models with more microscopic nuclear structure model input. The possible roles of nucleon and pair correlations and their observation using such reaction data are discussed.
Warner RE, Thompson IJ, Tostevin JA (2002) Effects of the in-medium NN interaction on total reaction and neutron removal cross sections,PHYSICAL REVIEW C 65 (4) ARTN 044617 AMERICAN PHYSICAL SOC
Davies PJ, Bentley MA, Henry TW, Simpson EC, Gade A, Lenzi SM, Baugher T, Bazin D, Berryman JS, Bruce AM, Aa. Diget C, Iwasaki H, Lemasson A, McDaniel S, Napoli DR, Ratkiewicz A, Scruton L, Shore A, Stroberg R, Tostevin JA, Weisshaar D, Wimmer K, Winkler R (2013) Mirror Energy Differences at Large Isospin Studied through Direct Two-Nucleon Knockout,Physical Review Letters 111 (7) 072501
The first spectroscopy of excited states in 52Ni (Tz=-2) and 51Co (Tz=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.
Wimmer K, Bazin D, Gade A, Tostevin JA, Baugher T, Chajecki Z, Coupland D, Famiano MA, Ghosh TK, Grinyer GF, Hodges R, Howard ME, Kilburn M, Lynch WG, Manning B, Meierbachtol K, Quarterman P, Ratkiewicz A, Sanetullaev A, Stroberg SR, Tsang MB, Weisshaar D, Winkelbauer J, Winkler R, Youngs M (2012) Probing elastic and inelastic breakup contributions to intermediate-energy two-proton removal reactions,PHYSICAL REVIEW C 85 (5) ARTN 051603
WINDHAM G, NISHIOKA H, TOSTEVIN JA, JOHNSON RC (1984) PROJECTILE EXCITATION EFFECTS ON VECTOR POLARIZED LI-6 SCATTERING FROM SI-28 AND O-16, PHYSICS LETTERS B 138 (4) pp. 253-256 ELSEVIER SCIENCE BV
Banerjee P, Thompson IJ, Tostevin JA (1998) Coulomb breakup of Be-11 and C-19,PHYSICAL REVIEW C 58 (2) pp. 1042-1051 AMERICAN PHYSICAL SOC
Liu XD, Famiano MA, Lynch WG, Tsang MB, Tostevin JA (2004) Systematic extraction of spectroscopic factors from C-12(d,p)C-13 and C-13(p,d)C-12 reactions,PHYSICAL REVIEW C 69 (6) ARTN 064313 AMERICAN PHYSICAL SOC
Enders J, Bauer A, Bazin D, Bonaccorso A, Brown BA, Glasmacher T, Hansen PG, Maddalena V, Miller KL, Navin A, Sherrill BM, Tostevin JA (2002) Single-neutron knockout from Si-34,Si-35 and S-37,PHYSICAL REVIEW C 65 (3) ARTN 034318 AMERICAN PHYSICAL SOC
Cupps VR, Brown JD, Foster CC, Jones WP, Miller DW, Nann H, Schwandt P, Stephenson EJ, Tostevin JA (1987) The 116Si(d, p)117Sn l=0 reaction mechanism at intermediate energies, Nuclear Physics, Section A 469 (3) pp. 445-466
We report measurements of the cross section, proton polarization, and deuteron vector (Ay) and tensor (Ayy) analyzing powers for the 116S(d, p)117)Sn reaction to the 1 2+ ground state of 117Sn at Ed = 79.0 MeV. The polarization was observed as the analyzing power in the time-reversed 117Sn(p, d)116Sn reaction. Adiabatic model calculations of the deuteron elastic channel reveal significant 3D-wave breakup contributions to the elastic cross section. Satisfactory agreement with the transfer reaction data is nevertheless obtained using adiabatic calculations which include only 3S-wave breakup and the bound deuteron D-state. The influence of the deuteron spin-orbit distortions on the polarization and vector analyzing power is reduced through a combination of the effects of angular momentum mismatch and deuteron channel absorption. © 1987.
Fallon P, Rodriguez-Vieitez E, Macchiavelli AO, Gade A, Tostevin JA, Adrich P, Bazin D, Bowen M, Campbell CM, Clark RM, Cook JM, Cromaz M, Dinca DC, Glasmacher T, Lee IY, McDaniel S, Mueller WF, Prussin SG, Ratkiewicz A, Siwek K, Terry JR, Weisshaar D, Wiedeking M, Yoneda K, Brown BA, Otsuka T, Utsuno Y (2010) Two-proton knockout from Mg-32: Intruder amplitudes in Ne-30 and implications for the binding of F-29,F-31,PHYSICAL REVIEW C 81 (4) ARTN 041302 AMER PHYSICAL SOC
TOSTEVIN JA, NELSON JM, KARBAN O, BASAK AK, ROMAN S (1984) DIRECT OBSERVATION OF THE ALPHA-PARTICLE D-STATE IN THE (D,ALPHA) REACTION, PHYSICS LETTERS B 149 (1-3) pp. 9-12 ELSEVIER SCIENCE BV
Rugmai S, Al-Khalili JS, Johnson RC, Tostevin JA (1999) Three-body effects in the (d,He-2) charge-exchange reaction,PHYSICAL REVIEW C 60 (2) ARTN 027002 AMERICAN PHYSICAL SOC
Tostevin JA (2006) Probing the shell model using nucleon knockout reactions,Journal of Physics: Conference Series 49 (1) pp. 21-26 Institute of Physics
Liu H, Lee J, Doornenbal P, Scheit H, Takeuchi S, Aoi N, Li K, Matsushita M, Steppenbeck D, Wang H, Baba H, Ideguchi E, Kobayashi N, Kondo Y, Lee G, Michimasa S, Motobayashi T, Sakurai H, Takechi M, Togano Y, Tostevin JA, Utsuno Y (2015) Single-Neutron Knockout Reaction from 30Ne,JPS Conference Proceedings 6 pp. 030003-1-030003-4
Intruder configurations in the ground state of 30Ne were studied using the one neutron knockout reaction 12C(30Ne,29Ne + ³)X at 228?MeV/nucleon at the Radioactive Isotope Beam Factory. Individual parallel momentum distributions and partial cross sections were measured by tagging ³ rays. A significant population of the p-wave intruder state in 29Ne is observed, providing further experimental evidence for the vanishing of the N = 20 shell closure.
Crawford HL, Fallon P, Macchiavelli AO, Clark RM, Brown BA, Tostevin JA, Bazin D, Aoi N, Doornenbal P, Matsushita M, Scheit H, Steppenbeck D, Takeuchi S, Baba H, Campbell CM, Cromaz M, Ideguchi E, Kobayashi N, Kondo Y, Lee G, Lee IY, Lee J, Li K, Michimasa S, Motobayashi T, Nakamura T, Ota S, Paschalis S, Petri M, Sako T, Sakurai H, Shimoura S, Takechi M, Togano Y, Wang H, Yoneda K (2014) Shell and shape evolution at N=28: The Mg40 ground state,Physical Review C: Nuclear Physics 89 041303
A measurement of the direct two-proton removal from Si42 has provided the first structural information on the N=28 isotone Mg40. The value for the inclusive cross section for two-proton removal from Si42 of 40+27?17 ¼b is significantly lower than that predicted by structure calculations using the recent SDPF-MU shell-model effective interaction combined with eikonal reaction theory. This observed discrepancy is consistent with the interpretation that only one of the predicted low-lying 0+ states in Mg40 is bound. A two-state mixing analysis describing two-proton knockout cross sections along N=28 provides support for the interpretation of a prolate-deformed Mg40 ground state.
Diaz-Torres A, Hinde DJ, Tostevin JA, Dasgupta M, Gasques LR (2007) Relating breakup and incomplete fusion of weakly bound nuclei through a classical trajectory model with stochastic breakup,PHYSICAL REVIEW LETTERS 98 (15) ARTN 152701 AMERICAN PHYSICAL SOC
Tostevin JA (2007) Reaction spectroscopy at fragmentation beam energies - recent advances in studies of two-nucleon removal,EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS 150 pp. 67-70 EDP SCIENCES S A
Davids B, Austin SM, Bazin D, Esbensen H, Sherrill BM, Thompson IJ, Tostevin JA (2002) Coulomb breakup of B-8 and the flux of B-8 neutrinos from the Sun, EUROPEAN PHYSICAL JOURNAL A 15 (1-2) pp. 65-68 SPRINGER-VERLAG
Mortimer J, Thompson IJ, Tostevin JA (2002) Higher-order and E2 effects in medium energy B-8 breakup,PHYSICAL REVIEW C 65 (6) ARTN 064619 AMERICAN PHYSICAL SOC
Frank N, Albertson D, Bailey J, Baumann T, Bazin D, Brown BA, Brown J, DeYoung PA, Finck JE, Gade A, Hinnefeld J, Howes R, Kasperczyk M, Luther B, Peters WA, Schiller A, Smith A, Thoennessen M, Tostevin JA (2011) Neutron-unbound states in F-25,F-26,PHYSICAL REVIEW C 84 (3) ARTN 037302 AMER PHYSICAL SOC
Terry JR, Bazin D, Brown BA, Enders J, Glasmacher T, Hansen PG, Sherrill BM, Tostevin JA (2004) Absolute spectroscopic factors from neutron knockout on the halo nucleus C-15,PHYSICAL REVIEW C 69 (5) ARTN 054306 AMERICAN PHYSICAL SOC
Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Gade A, Glasmacher T, Hansen PG, Mueller WF, Olliver H, Perry BC, Sherrill BM, Terry JR, Tostevin JA (2003) New direct reaction: Two-proton knockout from neutron-rich nuclei,PHYSICAL REVIEW LETTERS 91 (1) ARTN 012501 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA (2013) Cooper pair correlations and energetic knock-out reactions,In: Broglia RA, Zelevinsky V (eds.), Fifty Years of Nuclear BCS 35 World Scientific Publishing Company
Two-nucleon removal (or knock-out) reactions at intermediate energies are a developing tool for both nuclear spectroscopy and for the study of certain nucleon correlations in very exotic and some stable nuclei. We present an overview of these reactions with specific emphasis on the nature of the two-nucleon correlations that can be probed. We outline future possibilities and tests needed to fully establish these sensitivities.
The (p,t) transfer reaction is being studied for its potential use in surrogate reaction analyses. A theoretical model has been developed to predict spin-parity distributions of final states excited in the reaction. The model, after comparisons with experimental data, may provide a predictive capability to identify candidate isotopes for measurement. Preliminary results are presented for the 92Zr(p,t)90Zr reaction at incident proton energy Ep=28.5MeV. New experimental data for this reaction at a similar energy, and for several other stable Zr isotopes, will soon be available.
CRESPO R, JOHNSON RC, TOSTEVIN JA (1994) VALIDITY OF LOCAL-DENSITY PRESCRIPTIONS FOR MICROSCOPIC CALCULATIONS OF PROTON-NUCLEUS ELASTIC-SCATTERING,PHYSICAL REVIEW C 50 (6) pp. 2995-3009 AMERICAN PHYSICAL SOC
Brown BA, Hansen PG, Tostevin JA (2003) Comment on "Experimental evidence of core modification in the near drip-line nucleus O-23",PHYS REV LETT 90 (15) 159201 AMERICAN PHYSICAL SOC
Crespo R, Tostevin JA, Thompson IJ (1996) Structure signatures in proton scattering from Li-9,Li-11,PHYSICAL REVIEW C 54 (4) pp. 1867-1876 AMERICAN PHYSICAL SOC
Obertelli A, Gade A, Bazin D, Campbell CM, Cook JM, Cottle PD, Davies AD, Dinca DC, Glasmacher T, Hansen PG, Hoagland T, Kemper KW, Lecouey JL, Mueller WF, Reynolds RR, Roeder BT, Terry JR, Tostevin JA, Yoneda K, Zwahlen H (2006) Population of bound excited states in intermediate-energy fragmentation reactions,PHYSICAL REVIEW C 73 (4) ARTN 044605 AMERICAN PHYSICAL SOC
AlKhalili JS, Tostevin JA (1996) Matter radii of light halo nuclei,PHYSICAL REVIEW LETTERS 76 (21) pp. 3903-3906 AMERICAN PHYSICAL SOC
BROWN JD, BARNWELL JM, ROMAN S, CONZETT HE, EVERSHEIM D, LARIMER RM, BIRCHALL J, LAPOINTE C, MCKEE JSC, CLARKE NM, GRIFFITHS RJ, HANSPAL JS, MCCULLOCH RA, JOHNSON RC, TOSTEVIN JA (1985) SEPARATION OF PROJECTILE AND EJECTILE SPIN-ORBIT DISTORTIONS IN AN L=0 (D, HE-3) REACTION, NUCLEAR PHYSICS A 436 (1) pp. 125-138 ELSEVIER SCIENCE BV
TOSTEVIN JA, LOPES MH, JOHNSON RC (1987) ANTISYMMETRIZATION CORRECTIONS IN DEUTERON ELASTIC-SCATTERING AND DEUTERON-INDUCED TRANSFER-REACTIONS, NUCLEAR PHYSICS A 465 (1) pp. 83-122 ELSEVIER SCIENCE BV
Rodriguez-Gallardo M, Arias JM, Gomez-Camacho J, Moro AM, Thompson IJ, Tostevin JA (2005) Three-body continuum discretization in a basis of transformed harmonic oscillator states,PHYSICAL REVIEW C 72 (2) ARTN 024007 AMER PHYSICAL SOC
AlKhalili JS, Tostevin JA, Thompson IJ (1996) Radii of halo nuclei from cross section measurements,PHYSICAL REVIEW C 54 (4) pp. 1843-1852 AMERICAN PHYSICAL SOC
Alahari N, Bazin D, Brown BA, Davids B, Gervais G, Glasmacher T, Govaert K, Hansen PG, Hellstrom M, Ibbotson RW, Maddalena V, Pritychenko B, Scheit H, Sherrill BM, Steiner M, Tostevin JA, Yurkon J (1998) Spectroscopy of Al-25 and P-26,P-27,P-28 using high-energy stripping reactions, ENAM 98: EXOTIC NUCLEI AND ATOMIC MASSES 455 pp. 209-214 AMER INST PHYSICS
COLEY DA, TOSTEVIN JA (1988) THE ADIABATIC APPROXIMATION OF DEUTERON BREAK-UP EFFECTS FOR TRANSFER-REACTIONS AT MEDIUM ENERGY, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 14 (5) pp. L97-L102 IOP PUBLISHING LTD
Bartlett A, Gorres J, Mathews GJ, Otsuki K, Wiescher M, Frekers D, Mengoni A, Tostevin J (2006) Two-neutron capture reactions and the r process,PHYSICAL REVIEW C 74 (1) ARTN 015802 AMERICAN PHYSICAL SOC
KARBAN O, TOSTEVIN JA (1981) EFFECT OF THE DEUTERON-TR TENSOR POTENTIAL ON THE DETERMINATION OF THE TRITON AND THE HE-3-D-STATE PARAMETER D2, PHYSICS LETTERS B 103 (4-5) pp. 259-263 ELSEVIER SCIENCE BV
Gade A, Adrich P, Bazin D, Bowen MD, Brown BA, Campbell CM, Cook JM, Glasmacher T, Hosier K, McDaniel S, McGlinchery D, Obertelli A, Riley LA, Siwek K, Tostevin JA, Weisshaar D (2008) In-beam gamma-ray spectroscopy at the proton dripline: Al-23,PHYSICS LETTERS B 666 (3) pp. 218-221 ELSEVIER SCIENCE BV
Tostevin JA, Gade A (2014) Systematics of intermediate-energy single-nucleon removal cross sections,Physical Review C: Nuclear Physics 90 057602
There is now a large and increasing body of experimental data and theoretical analyses for reactions that remove a single nucleon from an intermediate-energy beam of neutron- or proton-rich nuclei. In each such measurement, one obtains the inclusive cross section for the population of all bound final states of the mass A?1 reaction residue. These data, from different regions of the nuclear chart, and that involve weakly and strongly bound nucleons, are compared with theoretical expectations. These calculations include an approximate treatment of the reaction dynamics and shell-model descriptions of the projectile initial state, the bound final states of the residues, and the single-particle strengths computed from their overlap functions. The results are discussed in the light of recent data, more exclusive tests of the eikonal dynamical description, and calculations that take input from more microscopic nuclear structure models.
Enders J, Baumann T, Brown BA, Frank NH, Hansen PG, Heckman PR, Sherrill BM, Stolz A, Thoennessen M, Tostevin JA, Tryggestad EJ, Typel S, Wallace MS (2003) Spectroscopic factors measured in inclusive proton-knockout reactions on B-8 and C-9 at intermediate energies,PHYSICAL REVIEW C 67 (6) ARTN 064301 AMERICAN PHYSICAL SOC
STEPHENSON EJ, BACHER AD, BERG GPA, CUPPS VR, FOSTER CC, HODIWALLA N, LI P, LISANTTI J, LOW DA, MILLER DW, OLMER C, OPPER AK, PARK BK, SAWAFTA R, WISSINK SW, TOSTEVIN JA, COLEY DA, JOHNSON RC (1990) ENHANCEMENT OF THE NEAR-SIDE COMPONENT IN QUASIADIABATIC CALCULATIONS OF THE ZN-66(D,P)ZN-67 REACTION,PHYSICAL REVIEW C 42 (6) pp. 2562-2572 AMERICAN PHYSICAL SOC
Spyrou A, Smith JK, Baumann T, Brown BA, Brown J, Christian G, Deyoung PA, Frank N, Mosby S, Peters WA, Schiller A, Strongman MJ, Thoennessen M, Tostevin JA (2011) Search for the 15Be ground state,Physical Review C - Nuclear Physics 84 (4)
Voss P, Baumann T, Bazin D, Dewald A, Iwasaki H, Miller D, Ratkiewicz A, Spyrou A, Starosta K, Thoennessen M, Vaman C, Tostevin JA (2014) Mg19 two-proton decay lifetime,Physical Review C: Nuclear Physics 90 014301 APS
The ground state two-proton decay lifetime of Mg19, populated by the one-neutron knockout of an intermediate-energy Mg20 radioactive beam, was measured utilizing a new experimental technique. A thin silicon detector positioned at varying distances (0.0?1.0 mm) downstream of the reaction target measured the energy loss of Mg19 and the two-proton decay product Ne17. The lifetime was deduced from fits to the measured energy-loss line shapes and depended upon the contribution of prompt reaction processes to the yield of Ne17. For relative Ne17 prompt contributions from 82% to 92%, the extracted lifetimes ranged from 1.75+0.43?0.42 to 6.4+2.4?2.7 ps. The results are consistent with the previously reported Mg19 lifetime measurement and serve as both an important complementary study and a validation of this new technique, which can provide lifetime information for short-lived states beyond the proton drip line.
Rodriguez-Gallardo M, Arias JM, Gomez-Camacho J, Johnson RC, Moro AM, Thompson IJ, Tostevin JA (2007) Continuum effects: Structure and reactions of He-6,EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS 150 pp. 51-52 SPRINGER HEIDELBERG
Tostevin JA, Batham P, Podolyak G, Thompson IJ (2004) Direct reaction spectroscopy of exotic nuclei,NUCLEAR PHYSICS A 746 pp. 166C-172C ELSEVIER SCIENCE BV
Schiller A, Frank N, Baumann T, Bazin D, Brown BA, Brown J, DeYoung PA, Finck JE, Gade A, Hinnefeld J, Howes R, Lecouey J-L, Luther B, Peters WA, Scheit H, Thoennessen M, Tostevin JA (2007) Selective population and neutron decay of an excited state of O-23,PHYSICAL REVIEW LETTERS 99 (11) ARTN 112501 AMER PHYSICAL SOC
Diaz-Torres A, Hinde DJ, Dasgupta M, Milburn GJ, Tostevin JA (2008) Dissipative quantum dynamics in low-energy collisions of complex nuclei,PHYSICAL REVIEW C 78 (6) ARTN 064604 AMER PHYSICAL SOC
Jones KL, Ahn S, Allmond JM, Ayres A, Bardayan DW, Baugher T, Bazin D, Beene JR, Berryman JS, Bey A, Bingham C, Burcher S, Cartegni L, Cerizza G, Chae KY, Cizewski JA, Gade A, Galindo-Uribarri A, Garcia-Ruiz RF, Grzywacz R, Howard ME, Kozub RL, Liang JF, Manning B, Matos M, McDaniel S, Miller D, Nesaraja CD, O'Malley PD, Padgett S, Padilla-Rodal E, Pain SD, Pittman ST, Radford DC, Ratkiewicz A, Schmitt KT, Shore A, Smith MS, Stracener DW, Stroberg SR, Tostevin J, Varner RL, Weisshaar D, Wimmer K, Winkler R (2015) Direct Reaction Experimental Studies with Beams of Radioactive Tin Ions, NUCLEAR STRUCTURE AND DYNAMICS '15 1681 AMER INST PHYSICS
Brown BA, Hansen PG, Sherrill BM, Tostevin JA (2002) Absolute spectroscopic factors from nuclear knockout reactions,PHYSICAL REVIEW C 65 (6) ARTN 061601 AMERICAN PHYSICAL SOC
Miller D, Adrich P, Brown BA, Moeller V, Ratkiewicz A, Rother W, Starosta K, Tostevin JA, Vaman C, Voss P (2009) Intermediate energy proton knockout to the "island of inversion" isotope Mg-31,PHYSICAL REVIEW C 79 (5) ARTN 054306 AMER PHYSICAL SOC
Gade A, Tostevin JA, Bader V, Baugher T, Bazin D, Berryman JS, Brown BA, Hartley DJ, Lunderberg E, Reccia F, Stroberg SR, Utsuno Y, Weisshaar D, Wimmer K (2016) One-neutron pickup into Ca49: Bound neutron g9/2 spectroscopic strength at N=29,Physical Review C: Nuclear Physics 93 031601(R)
The highly selective, intermediate-energy heavy-ion-induced neutron-pickup reaction, in combination with ³-ray spectroscopy using the ³-ray energy-tracking in-beam nuclear array (GRETINA), is shown to provide reliable relative spectroscopic strengths for high-? orbitals in nuclei more neutron rich than the projectile. The reaction mechanism gives a significant final-state-spin alignment that is validated through ³-ray angular-distribution measurements enabled by the position sensitivity of GRETINA. This is the first time that ³-ray angular distributions could be extracted from a high-luminosity, fast-beam reaction other than inelastic scattering. This holds great promise for the restriction and assignment of JÀ quantum numbers in exotic nuclei. We advance this approach to study the crucial N=28 shell closure and extract the ratio g9/2:f5/2 of bound neutron single-particle strengths in Ca49, a benchmark for emerging multi-shell ab initio and configuration-interaction theories that are applicable along the Ca isotopic chain.
Gade A, Janssens RVF, Bazin D, Brown BA, Campbell CM, Carpenter MP, Cook JM, Deacon AN, Dinca D-C, Freeman SJ, Glasmacher T, Horoi M, Kay BP, Mantica PF, Mueller WF, Terry JR, Tostevin JA, Zhu S (2006) One-neutron knockout in the vicinity of the N=32 sub-shell closure: Be-9(Cr-57,Cr-56+gamma)X,PHYSICAL REVIEW C 74 (4) ARTN 047302 AMERICAN PHYSICAL SOC
Zahar M, Belbot M, Kolata JJ, Lamkin K, Morrissey DJ, Sherrill BM, Lewitowicz M, Wuosmaa AH, Al-Khalili JS, Tostevin JA (1996) Quasielastic scattering of 9Li on 12C,Physical Review C - Nuclear Physics 54 (3) pp. 1262-1266 The American Physical Society
GODDARD RP, KNUTSON LD, TOSTEVIN JA (1982) DETERMINATION OF THE ASYMPTOTIC D-STATE TO S-STATE RATIO OF THE DEUTERON FROM SUB-COULOMB (D-],P) MEASUREMENTS, PHYSICS LETTERS B 118 (4-6) pp. 241-244 ELSEVIER SCIENCE BV
ALKHALILI JS, THOMPSON IJ, TOSTEVIN JA (1995) EVALUATION OF AN EIKONAL MODEL FOR LI-11-NUCLEUS ELASTIC-SCATTERING, NUCLEAR PHYSICS A 581 (2) pp. 331-355 ELSEVIER SCIENCE BV
Yoneda K, Obertelli A, Gade A, Bazin D, Brown BA, Campbell CM, Cook JM, Cottle PD, Davies AD, Dinca D-C, Glasmacher T, Hansen PG, Hoagland T, Kemper KW, Lecouey J-L, Mueller WF, Reynolds RR, Roeder BT, Terry JR, Tostevin JA, Zwahlen H (2006) Two-neutron knockout from neutron-deficient Ar-34, S-30, and Si-26,PHYSICAL REVIEW C 74 (2) ARTN 021303 AMERICAN PHYSICAL SOC
NISHIOKA H, JOHNSON RC, TOSTEVIN JA, KUBO KI (1982) SPIN-ORBIT INTERACTION INDUCED BY HEAVY-ION PROJECTILE EXCITATION,PHYSICAL REVIEW LETTERS 48 (26) pp. 1795-1798 AMERICAN PHYSICAL SOC
Howell DJ, Tostevin JA, Al-Khalili JS (2005) Coupled channels calculations of Be-11 breakup,JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 31 (10) pp. S1881-S1884 IOP PUBLISHING LTD
Bush MP, AlKhalili JS, Tostevin JA, Johnson RC (1996) Sensitivity of reaction cross sections to halo nucleus density distributions,PHYSICAL REVIEW C 53 (6) pp. 3009-3013 AMERICAN PHYSICAL SOC
STEPHENSON EJ, JOHNSON RC, TOSTEVIN JA, CUPPS VR, BROWN JD, FOSTER CC, GERING JA, JONES WP, LOW DA, MILLER DW, NANN H, OLMER C, OPPER AK, SCHWANDT P, SEUBERT JW, WISSINK SW (1986) IMPLICATIONS OF FAR-SIDE DOMINANCE FOR THE DISAGREEMENT BETWEEN DISTORTED-WAVE THEORY AND WELL-MATCHED INTERMEDIATE ENERGY (D, P) REACTIONS, PHYSICS LETTERS B 171 (4) pp. 358-362 ELSEVIER SCIENCE BV
TOSTEVIN JA (1985) THEORETICAL AND EMPIRICAL STATUS OF THE 2-DEUTERON ALPHA-PARTICLE VERTEX, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 11 (11) pp. L211-L217 IOP PUBLISHING LTD
Brooke JM, Al-Khalili JS, Tostevin JA (1999) Noneikonal calculations for few-body projectiles,PHYSICAL REVIEW C 59 (3) pp. 1560-1566 AMERICAN PHYSICAL SOC
Tostevin JA, Nunes FM, Thompson IJ (2001) Calculations of three-body observables in B-8 breakup,PHYS REV C 6302 (2) 024617 AMERICAN PHYSICAL SOC
Togano Y, Nakamura T, Kondo Y, Kobayashi N, Tanaka R, Minakata R, Ogoshi S, Nishi S, Kanno D, Nakashima T, Tsubota J, Saito T, Tostevin JA, Orr N, Gibelin J, Delaunay F, Marques F, Achouri N, Leblond S, Deshayes Q, Yoneda K, Motobayashi T, Otsu H, Isobe T, Baba H, Sato H, Shimizu Y, Kubo T, Inabe N, Fukuda N, Kameda D, Suzuki H, Takeda H, Lee J, Doornenbal P, Takeuchi S, Kobayashi T, Takahashi K, Muto K, Murakami T, Nakatsuka N, Satou Y, Kim S, Hwang J, Aumann T, Murai D, Navin A, Tuff A, Vandebrouck M (2016) Reaction Cross Section Of The Two-neutron Halo Nucleus 22C At 235 MeV/nucleon,
The reaction cross section (Ã R
ÃR
) of the very neutron-rich carbon isotope 22
22
C has been measured on a carbon target at 235 MeV/nucleon. A Ã R
ÃR
of 1.280±0.023
1.280±0.023
b was obtained for 22
22
C, significantly larger than those for the neighboring isotopes, supporting the halo character of 22
22
C. A 22
22
C root-mean-squared matter radius of 3.44±0.08
3.44±0.08
fm was deduced using a four-body Glauber reaction model. This value is smaller than an earlier estimate of 5.4±0.9
5.4±0.9
fm derived from a à R
ÃR
measurement on a hydrogen target at 40 MeV/nucleon.
Crawford H, Macchiavelli A, Fallon P, Albers M, Bader V, Bazin D, Campbell C, Clark R, Cromaz M, Dillin J, Gade A, Gallant A, Holt J, Janssens R, Krucken R, Langer C, Lauritsen T, Lee I, Menendez J, Noji S, Paschalis S, Recchia F, Rissanen J, Schwenk A, Scott M, Simonis J, Stroberg S, Tostevin JA, Walz C, Weisshaar D, Wiens A, Wimmer K, Zhu S (2017) Unexpected distribution of \nu1f7/2 strength in 49Ca,Physical Review C 95 (6) 064317 American Physical Society
The calcium isotopes have emerged as a critical testing ground for new microscopically derived
shell-model interactions, and a great deal of experimental and theoretical focus has been directed
toward this region. We investigate the relative spectroscopic strengths associated with 1f7=2 neutron
hole states in 47;49Ca following one-neutron knockout reactions from 48;50Ca. The observed reduction
of strength populating the 7/2
Scott M, Zegers R, Almus R, Austin S, Bazin D, Brown B, Campbell C, Gade A, Bowry M, Gales S, Garg U, Harakeh M, Kwan E, Langer C, Loelius C, Lipschutz S, Litvinova E, Lunderberg E, Morse C, Noji S, Perdikakis G, Redpath T, Robin C, Sakai H, Sasamoto Y, Sasano M, Sullivan C, Tostevin JA, Uesaka T, Weisshaar D (2017) Observation of the isovector giant monopole resonance via the 28Si(10Be,10B*[1.74 MeV]) reaction at 100 AMeV,Physical Review Letters 118 (17) 172501 American Physical Society
The (10Be,10B [1.74 MeV]) charge-exchange reaction at 100 AMeV is presented as a new probe for isolating the isovector (”T = 1) non-spin-transfer (”S = 0) response of nuclei, with 28Si being the rst nucleus studied. By using a secondary 10Be beam produced by fast fragmentation of 18O nuclei at the NSCL Coupled Cyclotron Facility, applying the dispersion-matching technique with the S800 magnetic spectrometer to determine the excitation energy in 28Al, and performing high- resolution -ray tracking with the Gamma-Ray Energy Tracking Array (GRETINA) to identify the 1022-keV ray associated with the decay from the 1.74-MeV T = 1 isobaric analog state in 10B, a ”S = 0 excitation-energy spectrum in 28Al was extracted. Monopole and dipole contributions were determined through a multipole-decomposition analysis, and the isovector giant dipole (IVGDR) and monopole (IVGMR) resonances were identi ed. The results show that this probe is a powerful tool for studying the elusive IVGMR, which is of interest for performing stringent tests of modern density functional theories at high excitation energies and for constraining the bulk properties of nuclei and nuclear matter. The extracted distributions were compared with theoretical calculations based on the normal-modes formalism and the proton-neutron relativistic time-blocking approximation. Calculated cross sections based on these strengths underestimate the data by about a factor of two, which likely indicates de ciencies in the reaction calculations based on the distorted wave Born approximation.
Bailey GW, Timofeyuk Natalia, Tostevin Jeffrey (2017) Nonlocal nucleon-nucleus interactions in (d,p) reactions: Role of the deuteron D state,Physical Review C: Nuclear Physics 95 (2) 024603 American Physical Society
Theoretical models of the (d, p) reaction are exploited for both nuclear astrophysics and spectroscopic studies in nuclear physics. Usually, these reaction models use local optical model potentials to describe the nucleon- and deuteron-target interactions. Within such a framework the importance of the deuteron D-state in low-energy reactions is normally associated with spin observables and tensor polarization effects - with very minimal influence on differential cross sections. In contrast, recent work that includes the inherent nonlocality of the nucleon optical model potentials in the Johnson-Tandy adiabatic-model description of the (d, p) transition amplitude, which accounts for deuteron break-up effects, shows sensitivity of the reaction to the large n-p relative momentum content of the deuteron wave function. The dominance of the deuteron D-state component at such high momenta leads to significant sensitivity of calculated (d, p) cross sections and deduced spectroscopic factors to the choice of deuteron wave function [Phys. Rev. Lett. 117, 162502 (2016)]. We present details of the Johnson-Tandy adiabatic model of the (d, p) transfer reaction generalized to include the deuteron D-state in the presence of nonlocal nucleon-target interactions. We present exact calculations in this model and compare these to approximate (leading-order) solutions. The latter, approximate solutions can be interpreted in terms of local optical potentials, but evaluated at a shifted value of the energy in the nucleon-target system. This energy shift is increased when including the D-state contribution. We also study the expected dependence of the D-state effects on the separation energy and orbital angular momentum of the transferred nucleon. Their influence on the spectroscopic information extracted from (d, p) reactions is quantified for a particular case of astrophysical significance.
Steppenbeck D., Takeuchi S., Aoi N., Doornenbal P., Matsushita M., Wang H., Baba H., Go S., Holt J.D., Lee J., Matsui K, Michimasa S., Motobayashi T., Nishimura D., Otsuka T, Sakurai H., Shiga Y., Söderström P-A., Stroberg S.R., Sumikama T, Taniuchi R., Tostevin Jeffrey, Utsuno Y., Valiente-Dobón J.J., Yoneda K. (2017) Structure of 55Sc and development of the N=34 subshell closure,Physical Review C 96 (6) 064310 pp. 064310-1 American Physical Society
The low-lying structure of 55Sc has been investigated using in-beam \gamma-ray spectroscopy with the 9Be(56Ti,55Sc+\gamma)X one-proton removal and 9Be(55Sc,55Sc+\gamma)X inelastic-scattering reactions at the RIKEN Radioactive Isotope Beam Factory. Transitions with energies of 572(4), 695(5), 1539(10), 1730(20), 1854(27), 2091(19), 2452(26), and 3241(39) keV are reported, and a level scheme has been constructed using \gamma\gamma coincidence relationships and \gamma-ray relative intensities. The results are compared to large-scale shell-model calculations in the sd-pf model space, which account for positive-parity states from proton-hole cross-shell excitations, and to {\it ab initio} shell-model calculations from the in-medium similarity renormalization group that includes three-nucleon forces explicitly. The results of proton-removal reaction theory with the eikonal model approach were adopted to aid identification of positive-parity states in the level scheme; experimental counterparts of theoretical 1/2+1 and 3/2+1 states are suggested from measured decay patterns. The energy of the first 3/2- state, which is sensitive to the neutron shell gap at the Fermi surface, was determined. The result indicates a rapid weakening of the N=34 subshell closure in pf-shell nuclei at Z>20, even when only a single proton occupies the \pi f7/2 orbital.
Vaquero V, Jungclaus A, Doornenbal P, Wimmer K, Gargano A, Tostevin JA, Chen S, Nacher E, Sahin E, Shiga Y, Steppenbeck D, Taniuchi R, Xu Z, Ando T, Baba H, Bello Garrote F, Franchoo S, Hadynska-Klek K, Kusoglu A, Liu J, Lokotko T, Momiyama S, Motobayashi T, Nagamine S, Nakatsuka N, Niikura M, Orlandi O, Saito T, Sakurai H, Soderstrom P, Tveten G, Vajta Z, Yalcinkaya M (2017) Gamma decay of unbound neutron-hole states in 133Sn,Physical Review Letters 118 202502 American Physical Society
Excited states in the nucleus 133Sn, with one neutron outside the doubly-magic 132Sn core, were populated following one-neutron knockout from a 134Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the rays emitted in the decay of the known neutron single-particle states in 133Sn additional strength in the energy range 3.5-5.5 MeV was observed for the fi rst time. Since the neutron-separation energy of 133Sn is low, Sn=2.402(4) MeV, this observation provides direct evidence for the radiative decay of neutron- unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These fi ndings suggest that in the region south-east of 132Sn nuclear structure effects may play a signifi cant role in the neutron vs. competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global b -decay properties for astrophysical simulations may have to be reconsidered.
Gade A, Tostevin Jeffrey, Bader V, Baugher T, Bazin D, Berryman JS, Brown BA, Diget C, Glasmacher T, Hartley DJ, Lunderberg E, Stroberg R, Recchia F, Ratkiewicz A, Weisshaar D, Wimmer K (2016) Single-particle structure at N=29: The structure of  47Ar and first spectroscopy of 45S,Physical Review C 93 (5) 054315 American Physical Society
Comprehensive spectroscopy of the N = 29 nucleus 47Ar is presented, based on two complemen-tary direct reaction mechanisms: one-neutron pickup onto 46Ar projectiles and one-proton removal from the 1? ground state of 48K. The results are compared to shell-model calculations that use the state-of-the-art SDPF-U and SDPF-MU e?ective interactions. Also, from the 9Be(46Cl,45S+³)X one-proton removal reaction, we report the ?rst ³-ray transitions observed from 45S. Using compar-isons with shell-model calculations, and from the observed intensities and energy sums, we propose a ?rst tentative level scheme for 45S.
Milne SA, Bentley MA, Simpson EC, Baugher T, Bazin D, Berryman JS, Bruce A, Davies PJ, Diget CA, Gade A, Henry TW, Iwasaki H, Lemasson A, Lenzi S, McDaniel S, Napoli DR, Nichols AJ, Ratkiewicz A, Scruton L, Stroberg SR, Tostevin Jeffrey, Weisshaar D, Wimmer K, Winkler R (2016) Isospin symmetry at high spin studied via nucleon knockout from isomeric states,Physical Review Letters 117 (8) 082502 American Physical Society
One-neutron knockout reactions have been performed on a beam of radioactive 53Co in a high-spin isomeric state. The analysis is shown to yield highly-selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11+ band-termination state, of the proton-rich nucleus 52Co (Z = 27, N = 25). This has in turn enabled a study of mirror energy differences in the A = 52 odd-odd mirror nuclei, interpreted in terms of isospin-non-conserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.
Togano Y, Nakamura T, Kondo Y, Tostevin Jeffrey, Saito AT, Gibelin J, Orr NA, Achouri NL, Aumann T, Baba H, Delaunay F, Doornenbal P, Fukuda N, Hwang J, Inabe N, Isobe T, Kameda D, Kanno D, Kimber S, Kobayashi N, Kobayashi T, Kubo T, Leblond S, Lee J, Marques FM, Minakata R, Motobayashi T, Murai D, Murakami T, Muto K, Nakashima T, Nakatsuka N, Navin A, Nishi S, Ogoshi S, Otsu H, Sato H, Satou Y, Shimizu Y, Suzuki H, Takahashi K, Takeda H, Takeuchi S, Tanaka R, Tuff AG, Vandebrouck M, Yoneda K (2016) Interaction cross section study of the two-neutron halo nucleus 22C,Physics Letters B 761 pp. 412-418 Elsevier
The interaction cross sections (ÃI ) of the very neutron-rich carbon isotopes 19C, 20C and 22C have been measured on a carbon target at 307, 280, and 235 MeV/nucleon, respectively. A ÃI of 1.280±0.023 b was obtained for 22C, significantly larger than for 19,20C, supporting the halo character of 22C. A 22C root-mean-squared matter radius of 3.44 ± 0.08 fm was deduced using a four-body Glauber reaction model. This value is smaller than an earlier estimate (of 5.4 ± 0.9 fm) derived from a ÃI measurement on a hydrogen target at 40 MeV/nucleon. These new, higher-precision ÃI data provide stronger constraints for assessing the consistency of theories describing weakly bound nuclei.
Mutschler A, Lemasson A, Sorlin O, Bazin D, Borcea C, Borcea R, Dombradi Z, Ebran J, Gade A, Iwasaki H, Khan E, Lepailleur A, Recchia F, Roger T, Rotaru F, Sohler D, Stanoiu M, Stroberg S, Tostevin JA, Vandebrouck M, Weisshaar D, Wimmer K (2016) A proton density bubble in the doubly-magic 34Si nucleus,Nature Physics 13 pp. 152-156 Nature Publishing Group
Many properties of the atomic nucleus, such as vibra- 21 tions, rotations and incompressibility can be interpreted 22 as due to a two-component quantum liquid of protons and 23 neutrons. Electron scattering measurements on stable nu- 24 clei demonstrate that their central densities are saturated, 25 as for liquid drops. In exotic nuclei near the limits of mass 26 and charge, with large imbalances in their proton and neu- 27 tron numbers, the possibility of a depleted central density, 28 or a ?bubble? structure, was discussed in a recurrent man- 29 ner since the seventies. Here we report first experimental 30 evidence that points to a depletion of the central density of protons in the short-lived nucleus 34 31 Si. The proton-toneutron density asymmetry in 34 32 Si offers the possibility to 33 place constraints on the density and isospin dependence 34 of the spin-orbit force - on which nuclear models have dis- 35 agreed for decades- and on its stabilizing effect towards 36 limits of nuclear existence
Pang DY, Timofeyuk Natalia, Johnson Ronald, Tostevin Jeffrey (2013) Rapid convergence of the Weinberg expansion of the deuteron stripping amplitude,Physical Review C: Nuclear Physics 87 064613
Theories of (d,p) reactions frequently use a formalism based on a transition amplitude that is dominated by the components of the total three-body scattering wave function where the spatial separation between the incoming neutron and proton is confined by the range of the n-p interaction, Vnp. By comparison with calculations based on the continuum discretized coupled channels method we show that the (d,p) transition amplitude is dominated by the first term of the expansion of the three-body wave function in a complete set of Weinberg states. We use the 132Sn(d,p)133Sn reaction at 30 and 100 MeV as examples of contemporary interest. The generality of this observed dominance and its implications for future theoretical developments are discussed.
Timofeyuk N, Thompson I, Tostevin JA (2008) Single-particle motion at large distances in 2N+core cluster systems near the drip line: a challenge for nuclear theory and experiment,Journal of Physics: Conference Series 111 (1) 012034
There exists a class of nuclei that are obtained by adding one nucleon to a loosely-bound nucleon-core system, for example $^{12}$Be, $^9$C, $^{18}$Ne. For such nuclei, one-nucleon overlap integrals that represent single-particle motion can strongly differ from the standard ones due to the correlations between the two nucleons above the core. The possible non-standard overlap behaviour should be included in the interpretation of the experimental data derived from one nucleon removal reactions such as knockout, transfer and breakup, as well as the predictions of low-energy nucleon capture that leads to these nuclei. We investigate the non-standard behaviour within a three-body model and discuss the challenges associated with this problem.
Shand C, Podolyak Z, Górska M, Doornenbal P, Obertelli A, Nowacki F, Otsuka T, Sieja K, Tostevin J, Tsunoda Y, Authelet G, Baba H, Calvet D, Château A, Chen S, Corsi A, Delbart A, Gheller J, Giganon A, Gillibert A, Isobe T, Lapoux V, Matsushita M, Momiyama S, Motobayashi T, Niikura M, Otsu H, Paul N, Péron C, Peyaud A, Pollacco E, Roussé J, Sakurai H, Santamaria C, Sasano M, Shiga Y, Steppenbeck D, Takeuchi S, Taniuchi R, Uesaka T, Wang H, Yoneda K, Ando T, Arici T, Blazhev A, Browne F, Bruce A, Carroll R, Chung L, Cortés M, Dewald M, Ding B, Dombrádi Z, Flavigny F, Franchoo S, Giacoppo F, Gottardo A, HadyDska-Kl?k K, Jungclaus A, Korkulu Z, Koyama S, Kubota Y, Lee J, Lettmann M, Linh B, Liu J, Liu Z, Lizarazo C, Louchart C, Lozeva R, Matsui K, Miyazaki T, Moschner K, Nagamine M, Nakatsuka N, Nishimura S, Nita C, Nobs C, Olivier L, Ota S, Orlandi R, Patel Z, Regan P, Rudigier M, ^ahin E, Saito T, Söderström P, Stefan I, Sumikama T, Suzuki D, Vajta Z, Vaquero V, Werner V, Wimmer K, Wu J, Xu Z (2017) Shell evolution beyond Z = 28 and N = 50: Spectroscopy of 81,82,83,84 Zn,Physics Letters B 773 pp. 492-497 Elsevier
We report on the measurement of new low-lying states in the neutron-rich 81,82,83,84Zn nuclei via in-beam ³ -ray spectroscopy. These include the View the MathML source41+’21+ transition in 82Zn, the View the MathML source21+’0g.s.+ and View the MathML source41+’21+ transitions in 84Zn, and low-lying states in 81,83Zn were observed for the first time. The reduced View the MathML sourceE(21+) energies and increased View the MathML sourceE(41+)/E(2+1) ratios at N=52N=52, 54 compared to those in 80Zn attest that the magicity is confined to the neutron number N=50N=50 only. The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations. The newly observed 2+2+ and 4+4+ levels in 84Zn suggest the onset of deformation towards heavier Zn isotopes, which has been incorporated by taking into account the upper sdg orbitals in the Ni78-II and the PFSDG-U models.
Bailey G, Timofeyuk N, Tostevin J (2016) Sensitivity of (d,p) reactions to high n-p momenta and the consequences for nuclear spectroscopy studies,Physical Review Letters 117 (16) 162502 American Physical Society
Theoretical models of low-energy (d,p) single-neutron transfer reactions are a crucial link between experimentation, nuclear structure and nuclear astrophysical studies. Whereas reaction models that use local optical potentials are insensitive to short-range physics in the deuteron, we show that including the inherent nonlocality of the nucleon-target interactions and realistic deuteron wave functions generates significant sensitivity to high n-p relative momenta and to the underlying nucleon-nucleon interaction. We quantify this effect upon the deuteron channel distorting potentials within the framework of the adiabatic deuteron breakup model. The implications for calculated (d,p) cross sections and spectroscopic information deduced from experiments are discussed.
Liu H, Lee J, Doornenbal P, Scheit H, Takeuchi S, Aoi N, Li K, Matsushita M, Steppenbeck D, Wang H, Baba H, Ideguchi E, Kobayashi N, Kondo Y, Lee G, Michimasa S, Motobayashi T, Poves A, Sakurai H, Takechi M, Togano Y, Tostevin J, Utsuno Y (2017) Intruder configurations in the ground state of 30Ne,Physics Letters Section B: Nuclear, Elementary Particle and High-Energy Physics 767 pp. 58-62 Elsevier
We report on the first detailed study of intruder configurations in the ground state of 30Ne by means of the 12C(30Ne,29Ne+³)X one-neutron knockout reaction at 228 MeV/nucleon. Using a combined analysis of individual parallel momentum distributions and partial cross sections we find: (a) comparable p- and d-wave removal strength to 29Ne final states with excitation energies below 200 keV, and (b) significant p-wave removal strength to the 620 keV state of 29Ne, and (c) no evidence for f-wave intruder strength leading to bound 29Ne final states. The SDPF-U-MIX shell model calculation in the sd-pf model space provides a better overall agreement with the measured energy levels of 29Ne and the fp-intruder amplitudes in 30Ne than the SDPF-M prediction, suggesting that the refinement of the sd-pf cross shell interaction and extension of the model space to include the 2p1/2 and 1f5/2 levels are important for understanding the island of inversion.
Recchia F., Weisshaar D., Gade A., Tostevin Jeffrey, Janssens R. V. F., Albers M., Bader V. M., Baugher T., Bazin D., Berryman J. S., Brown B. A., Campbell C. M., Carpenter M. P., Chen J., Chiara C. J., Crawford H. L., Hoffman C. R., Kondev F. G., Korichi A., Langer C., Lauritsen T., Liddick S. N., Lunderberg E., Macchiavelli A. O., Noji S., Stroberg S. R., Suchyta S., Williams S., Wimmer K., Zhu S. (2018) Neutron knockout from 68,70Ni ground and isomeric states,Journal of Physics: Conference Series 966 IOP Publishing
Neutron-rich isotopes are an important source of new information on nuclear physics.
Specifically, the spin-isospin components in the nucleon-nucleon (NN) interaction, e.g., the
proton-neutron tensor force, are expected to modify shell structure in exotic nuclei. These
potential changes in the intrinsic shell structure are of fundamental interest. The study of
the excitation energy of states corresponding to specific configurations in even-even isotopes,
together with the single-particle character of the first excited states of odd-A, neutron-rich Ni
isotopes, probes the evolution of the neutron orbitals around the Fermi surface as a function
of the neutron number a step forward in the understanding of the region and the nature of the
NN interaction at large N/Z ratios.
In an experiment carried out at the National Superconducting Cyclotron Laboratory, new
spectroscopic information was obtained for 68Ni and the distribution of single-particle strengths
in 67
,
69Ni was characterized by means of single-neutron knockout from 68
,
70Ni secondary beams.
The spectroscopic strengths, deduced from the measured partial cross sections to the individual
states tagged by their de-exciting gamma rays, is used to identify and quantify configurations
that involve neutron excitations across the N = 40 harmonic oscillator shell closure. The de-
excitation
rays were measured with the GRETINA tracking array.
The results challenge the validity of the most current shell-model Hamiltonians and effective
interactions, highlighting shortcomings that cannot yet be explained. These results suggest that
our understanding of the low-energy states in such nuclei is not complete and requires further
investigation.

The contributions to the cross sections of intermediate energy two-nucleon knockout reactions from events in which one nucleon is removed by the stripping (inelastic breakup) mechanism and a second by the diffraction (elastic breakup) mechanism are discussed. The small additional contributions from two-nucleon diffraction events are also estimated. The approach used combines the eikonal reaction and shell model structure theory frameworks. For reactions involving the removal of two well-bound like nucleons, at incident energies of order 100 MeV per nucleon, the additional cross sections are shown to be of approximately the same size as those from events in which both nucleons are stripped in inelastic interactions. These more complete dynamical calculations now permit a quantitative comparison of the theoretical cross sections with recent partial cross-section measurements of the two-neutron (two-proton) removal reactions from neutron-deficient (neutron-rich) nuclei. As has been observed in both nuclear- and electron-induced single-nucleon knockout reaction analyses, the theoretical two-nucleon knockout cross sections overestimate the measured values, requiring a suppression of the two nucleon shell-model transition strengths. The deduced two-nucleon suppression factors, Rs(2N), are consistent with a value of 0.5 for each of the five reactions considered.

Obertelli A, Gade A, Bazin D, Campbell C M, Cook J M, Cottle P D, Davies A D, Dinca D C, Glasmacher T, Hansen P G, Hoagland T, Kemper K W, Lecouey J L, Mueller W F, Reynolds R R, Roeder B T, Terry J R, Tostevin J A, Yoneda K, Zwahlen H (2006) Population of Bound Excited States in Intermediate-Energy Fragmentation Reactions,Physical Review C 73 (4)

Fragmentation reactions with intermediate-energy heavy-ion beams exhibit a wide range of reaction mechanisms, ranging from direct reactions to statistical processes. We examine this transition by measuring the relative population of excited states in several sd-shell nuclei produced by fragmentation with the number of removed nucleons ranging from two to sixteen. The two-nucleon removal is consistent with a non-dissipative process, whereas the removal of more than five nucleons appears to be mainly statistical.

Diaz-Torres A, Hinde D J, Tostevin J A, Dasgupta M, Gasques L R (2007) Relating Breakup and Incomplete Fusion of Weakly Bound Nuclei Through a Classical Trajectory Model with Stochastic Breakup,Physical Review Letters 98 (15)

A classical dynamical model that treats breakup stochastically is presented for low energy reactions of weakly bound nuclei. The three-dimensional model allows a consistent calculation of breakup, incomplete, and complete fusion cross sections. The model is assessed by comparing the breakup observables with continuum discretized coupled-channel quantum mechanical predictions, which are found to be in reasonable agreement. Through the model, it is demonstrated that the breakup probability of the projectile as a function of its distance from the target is of primary importance for understanding complete and incomplete fusion at energies near the Coulomb barrier.

Diaz-Torres A., Hinde D. J., Tostevin J. A., Dasgupta M., Gasques L. R. (2007) Relating Breakup and Incomplete Fusion of Weakly Bound Nuclei through a Classical Trajectory Model with Stochastic Breakup,Physical Review Letters 98 (152701)

A classical dynamical model that treats breakup stochastically is presented for low energy reactions of weakly bound nuclei. The three-dimensional model allows a consistent calculation of breakup, incomplete, and complete fusion cross sections. The model is assessed by comparing the breakup observables with continuum discretized coupled-channel quantum mechanical predictions, which are found to be in reasonable agreement. Through the model, it is demonstrated that the breakup probability of the projectile as a function of its distance from the target is of primary importance for understanding complete and incomplete fusion at energies near the Coulomb barrier.

Obertelli A., Gade A., Bazin D., Campbell C. M., Cook J. M., Cottle P. D., Davies A. D., Dinca D.-C., Glasmacher T., Hansen P. G., Hoagland T., Kemper K. W., Lecouey J.-L., Mueller W. F., Reynolds R. R., Roeder B. T., Terry J. R., Tostevin J. A., Yoneda K., Zwahlen Y. (2006) Population of bound excited states in intermediate-energy fragmentation reactions,Physical Review C 73 (044605)

Fragmentation reactions with intermediate-energy heavy-ion beams exhibit a wide range of reaction mechanisms, ranging from direct reactions to statistical processes. We examine this transition by measuring the relative population of excited states in several sd-shell nuclei produced by fragmentation with the number of removed nucleons ranging from two to sixteen. The two-nucleon removal is consistent with a non-dissipative process, whereas the removal of more than five nucleons appears to be mainly statistical.

The contributions to the cross sections of intermediate energy two-nucleon knockout reactions from events in which one nucleon is removed by the stripping (inelastic breakup) mechanism and a second by the diffraction (elastic breakup) mechanism are discussed. The small additional contributions from two-nucleon diffraction events are also estimated. The approach used combines the eikonal reaction and shell model structure theory frameworks. For reactions involving the removal of two well-bound like nucleons, at incident energies of order 100 MeV per nucleon, the additional cross sections are shown to be of approximately the same size as those from events in which both nucleons are stripped in inelastic interactions. These more complete dynamical calculations now permit a quantitative comparison of the theoretical cross sections with recent partial cross-section measurements of the two-neutron (two-proton) removal reactions from neutron-deficient (neutron-rich) nuclei. As has been observed in both nuclear- and electron-induced single-nucleon knockout reaction analyses, the theoretical two-nucleon knockout cross sections overestimate the measured values, requiring a suppression of the two nucleon shell-model transition strengths. The deduced two-nucleon suppression factors, R-s(2N), are consistent with a value of 0.5 for each of the five reactions considered.

Gade A, Bazin D, Brown BA, Campbell CM, Church JA, Dinca DC, Enders J, Glasmacher T, Hansen PG, Hu Z, Kemper KW, Mueller WF, Olliver H, Perry BC, Riley LA, Roeder BT, Sherrill BM, Terry JR, Tostevin JA, Yurkewicz KL (2004) One-neutron knockout reactions on proton-rich nuclei with N=16,PHYS REV C 69 (3) 034311 pp. ?-? AMERICAN PHYSICAL SOC

One-neutron knockout reactions from the deeply bound N=16 isotones with Z=16,17, and 18 have been studied in inverse kinematics with intermediate-energy beams. gamma-ray spectroscopy in coincidence with the detection of knockout residues allowed for an investigation of the one-neutron removal leading to individual excited states. Spectroscopic factors are deduced in the framework of the sudden and eikonal approximations and are compared to USD shell-model predictions. The momentum distributions observed in the experiment are used to identify the angular momentum l carried by the knockedout neutron by comparing with calculations based on a black-disk reaction model. The systematics of reduced single-particle occupancies attributed to the effect of short-range correlations, observed so far for stable and near-magic nuclei in (e,e(')p) and (d,He-3) reactions and in one-nucleon knockout on light deeply bound systems, are extended in this work.

Gade A, Adrich P, Bazin D, Bowen M D, Brown B A, Campbell C M, Cook J M, Glasmacher T, Hansen P G, Hosier K, McDaniel S, McGlinchery D, Obertelli A, Siwek K, Riley L A, Tostevin J A, Weisshaar D (2008) Reduction of Spectroscopic Strength: Weakly-Bound and Strongly-Bound Single-Particle States Studied Using One-Nucleon Knockout Reactions,Physical Review C 77 (4)

Both one-proton and one-neutron knockout reactions were performed with fast beams of two asymmetric, neutron-deficient rare isotopes produced by projectile fragmentation. The reactions are used to probe the nucleon spectroscopic strengths at both the weakly and strongly bound nucleon Fermi surfaces. The one-proton knockout reactions Be-9(S-28, P-27)X and Be-9(Si-24, Al-23)X probe the weakly bound valence proton states and the one-neutron knockout reactions and Be-9(S-28, S-27)X and Be-9(Si-24, Si-23)X the strongly bound neutron states in the two systems. The spectroscopic strengths are extracted from the measured cross sections by comparisons with an eikonal reaction theory. The reduction of the experimentally deduced spectroscopic strengths, relative to the predictions of shell-model calculations, is of order 0.8-0.9 in the removal of weakly bound protons and 0.3-0.4 in the knockout of the strongly bound neutrons. These results support previous studies at the extremes of nuclear binding and provide further evidence that in asymmetric nuclear systems the nucleons of the deficient species, at the more-bound Fermi surface are more strongly correlated than those of the more weakly bound excess species.

Gade A, Adrich P, Bazin D, Bowen M D, Brown B A, Campbell C M, Cook J M, Glasmacher T, Hosier K, McDaniel S, McGlinchery D, Obertelli A, Riley L A, Siwek K, Tostevin J A, Weisshaar D (2007) Inverse-Kinematics One-Proton Pickup with Intermediate-Energy Beams: The Be-9 (Ne-20,Na-21+gamma)X Reaction,Physical Review C 76 (6)

The possibility of studying particle-like states near the Fermi surfaces of exotic nuclei by using measurements of heavy-ion-induced single-nucleon pickup reactions with in-flight separated rare-isotope beams is discussed. The analysis of an exploratory data set for the intermediate-energy Be-9(Ne-20,Na-21)X proton pickup reaction measured using a Ne-20 beam at 63 MeV per nucleon is reported. The data are compared with expectations based on model calculations of the transfer reaction cross sections and the Na-21 residue spectroscopy prediction by the sd-shell model. The measured cross sections are broadly consistent with these expectations.

Gade A., Adrich P., Bazin D., Bowen M. D., Brown B. A., Campbell C. M., Cook J. M., Glasmacher T., Hansen P. G., Hosier K., McDaniel S., McGlinchery D., Obertelli A., Siwek K., Riley L. A., Tostevin J. A., Weisshaar D. (2008) Reduction of spectroscopic strength: Weakly-bound and strongly-bound single-particle states studied using one-nucleon knockout reactions,Physical Review C 77 (044306)

Bothone-proton and one-neutron knockout reactions were performed with fast beamsof two asymmetric, neutron-deficient rare isotopes produced by projectile fragmentation.The reactions are used to probe the nucleon spectroscopic strengthsat both the weakly and strongly bound nucleon Fermi surfaces.The one-proton knockout reactions 9Be(28S,27P)X and 9Be(24Si,23Al)X probe the weaklybound valence proton states and the one-neutron knockout reactions and9Be(28S, 27S)X and 9Be(24Si, 23Si)X the strongly bound neutron statesin the two systems. The spectroscopic strengths are extracted fromthe measured cross sections by comparisons with an eikonal reactiontheory. The reduction of the experimentally deduced spectroscopic strengths, relativeto the predictions of shell-model calculations, is of order 0.8?0.9in the removal of weakly bound protons and 0.3?0.4 inthe knockout of the strongly bound neutrons. These results supportprevious studies at the extremes of nuclear binding and providefurther evidence that in asymmetric nuclear systems the nucleons ofthe deficient species, at the more-bound Fermi surface are morestrongly correlated than those of the more weakly bound excessspecies.

Terry J R, Brown B A, Campbell C M, Cook J M, Davies A D, Dinca D C, Gade A, Glasmacher T, Hansen P G, Sherrill B M, Zwahlen H, Bazin D, Yoneda K, Tostevin J A, Otsuka T, Utsuno Y, Pritychenko B (2008) Single-Neutron Knockout from Intermediate Energy Beams of Mg-30,Mg-32: Mapping the Transition into the "Island of Inversion",Physical Review C 77 (1)

The breakdown of the N=20 magic number in the so-called island of inversion around Mg-32 is well established. Recently developed large-scale shell-model calculations suggest a transitional region between normal- and intruder-dominated nuclear ground states, thus modifying the boundary of the island of inversion. In particular, a dramatic change in single-particle structure is predicted between the ground states of Mg-30 and Mg-32, with the latter consisting nearly purely of 2p-2h N=20 cross-shell configurations. Single-neutron knockout experiments on Mg-30,Mg-32 projectiles have been performed. We report on a first direct observation of intruder configurations in the ground states of these very neutron-rich nuclei. Spectroscopic factors to low-lying negative-parity states in the knockout residues are deduced and compare well with shell-model predictions.

Divaratne D. A., Brune C. R., Attanayake H. N., Baumann T., Bazin D., Gade A., Grimes S. M.., King P. M., Thoennessen M., Tostevin J. A. (2018) One- and two-neutron removal cross sections of 24O,Physical Review C 98 (2) 024306 pp. 024306-1 - 024306-8 American Physical Society
Cross sections of one- and two-neutron removal reactions of 24O, leading to the 23O(½+) ground
state and to bound final states of 22O, have been measured at the National Superconducting Cyclotron
Laboratory. The experiment was conducted using the S800 spectrograph and a 24O beam
energy of 92.3 MeV/u. The measured 23O ground state and 22O inclusive cross section values,
of 74(11) mb and 146(33) mb, respectively, are in good agreement with calculations using eikonal
reaction dynamics and shell-model nuclear structure overlaps. The widths at half maximum of
the associated parallel momentum distributions of these cross sections, deduced from Gaussian fits,
are 115(13) MeV/c for 23O and 309(36) MeV/c for 22O in the projectile rest frame. The data
and calculations strongly support the shell-model description of 24O as a spherical, doubly-magic
structure.
Orlandi R, Pain SD, Ahn S, Jungclaus A, Schmitt KT, Bardayan DW, Catford Wilton, Chapman R, Chipps KA, Cizewski JA, Gross CG, Howard ME, Jones KL, Kozub RL, Manning B, Matos M, Nishio K, O? Malley PD, Peters WA, Pittman ST, Ratkiewicz A, Shand Callum, Smith JF, Smith MS, Fukui T, Tostevin Jeffrey, Utsuno Y (2018) Neutron-hole states in 131Sn and spin-orbit splitting in neutron-rich nuclei,Physics Letters B 785 pp. 615-620 Elsevier
In atomic nuclei, the spin-orbit interaction originates from the coupling of the orbital motion of a nucleon with its intrinsic spin.
Recent experimental and theoretical works have suggested a weakening of the spin-orbit interaction in neutron-rich nuclei far from
stability. To study this phenomenon, we have investigated the spin-orbit energy splittings of single-hole and single-particle valence
neutron orbits of 132Sn. The spectroscopic strength of single-hole states in 131Sn was determined from the measured differential
cross sections of the tritons from the neutron-removing 132Sn(d,t)131Sn reaction, which was studied in inverse kinematics at the
Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spectroscopic factors of the lowest 3=2+, 1=2+
and 5=2+states were found to be (2 j+1), confirming the robust N = 82 shell closure at 132Sn. We compared the spin-orbit
splitting of neutron single-hole states in 131Sn to those of single-particle states in 133Sn determined in a recent measurement of the
132Sn(d,p)133Sn reaction. We found a significant reduction of the energy splitting of the weakly bound 3p orbits compared to the
well-bound 2d orbits, and that all the observed energy splittings can be reproduced remarkably well by calculations using a onebody
spin-orbit interaction and a Woods-Saxon potential of standard radius and diffuseness. The observed reduction of spin-orbit
splitting can be explained by the extended radial wavefunctions of the weakly bound orbits, without invoking a weakening of the
spin-orbit strength.
Murray I., MacCormick M., Bazin D., Doornenbal P., Aoi N., Baba H., Crawford H., Fallon P., Li K., Lee J., Matsushita M., Motobayashi T., Otsuka T., Sakurai H., Scheit H., Steppenbeck D., Takeuchi S., Tostevin J. A., Tsunoda N., Utsuno Y., Wang H., Yoneda K. (2019) Spectroscopy of strongly deformed 32Ne by proton knockout reactions,Physical Review C 99 (1) pp. 011302-1-011302-7 American Physical Society
Low lying states of neutron-rich 32Ne were populated by means of one- and two-proton knock-
out reactions at the RIKEN Radioactive Isotope Beam Factory. A new transition is observed at
1410(15) keV and assigned to the 4+
1 ’ 2+
1 decay. With this energy the R4/2 ratio is calculated to
be 2.99(6), lying close to the rigid rotor limit and suggests a high degree of collectivity and strongest
deformation among neutron-rich Neon isotopes. Comparisons of experimental inclusive and exclu-
sive reaction cross sections with shell model and eikonal reaction dynamical calculations reveals
considerable quenching for this highly asymmetric system and contributes to systematic trends.
Gade A., Janssens R. V. F., Tostevin J. A., Bazin D., Belarge J., Bender P. C., Bottoni S., Carpenter M. P., Elman B., Freeman S. J., Lauritsen T., Lenzi S. M., Longfellow B., Lunderberg E., Poves A., Riley L. A., Sharp D. K., Weisshaar D., Zhu S. (2019) Structure of 70Fe: Single-particle and collective degrees of freedom,Physical Review C 99 (1) 011301 pp. 011301-1 American Physical Society
Excited states in the neutron-rich 70Fe nucleus were populated in a one-proton removal reaction
from 71Co projectiles at 87 MeV/nucleon. A new transition was observed with the
³-ray tracking
array GRETINA and shown to feed the previously assigned 4+
1 state. In comparison to reaction
theory calculations with shell-model spectroscopic factors, it is argued that the new ³ ray possibly
originates from the 6+
1 state. It is further shown that the Doppler-reconstructed
³-ray spectra
are sensitive to the very different lifetimes of the 2+ and 4+ states, enabling their approximate
measurement. The emerging structure of 70Fe is discussed in comparison to LNPS-new large-scale
shell-model calculations.
Spieker M., Gade A., Weisshaar D., Brown B. A., Tostevin J.A., Longfellow B., Adrich P., Bazin D., Bentley M. A., Brown J. R., Campbell C. M., Diget C. Aa., Elman B., Glasmacher T., Hill M., Pritychenko B., Ratkiewicz A., Rhodes D. (2019) One-proton and one-neutron knockout reactions from N = Z = 28 56Ni to the A = 55 mirror pair 55Co and 55Ni,Physical Review C 99 (5) 051304(R) pp. 051304-1 American Physical Society
We present a high-resolution in-beam
³-ray spectroscopy study of excited states in the mirror
nuclei 55Co and 56Ni following one-nucleon knockout from a projectile beam of 56Ni. The newly
determined partial cross sections and the
³-decay properties of excited states provide a test of
state-of-the-art nuclear structure models and probe mirror symmetry in unique ways. The new
experimental data are compared to large-scale shell-model calculations in the full pf space and
including charge-dependent contributions. A mirror asymmetry for the partial cross sections leading
to the two lowest 3/2? states in the A = 55 mirror pair was identified as well as a significant difference
in the E1 decays from the 1/21+ state to the same two 3/2? states. The mirror asymmetry in
the partial cross sections cannot be reconciled with the present shell-model picture or small mixing
introduced in a two-state model. The observed mirror asymmetry in the E decay pattern, however,
points at stronger mixing between the two lowest 3/2? states in 55Co than in its mirror 55Ni.
Gade A., Brown B.A., Tostevin J. A., Bazin D., Bender P. C., Campbell C.M., Crawford H. L., Elman B., Kemper K. W., Longfellow B., Lunderberg E., Rhodes D., Weisshaar D. (2019) Is the structure of 42Si understood?,Physical Review Letters 122 (22) 222501 pp. 222501-1 - 222501-6 American Physical Society
A more detailed test of the implementation of nuclear forces that drive shell evolution in the
pivotal nucleus 42Si ? going beyond earlier comparisons of excited-state energies ? is important. The
two leading shell-model effective interactions, SDPF-MU and SDPF-U-Si, both of which reproduce
the low-lying 42Si(2+
1) energy, but whose predictions for other observables differ significantly, are
interrogated by the population of states in neutron-rich 42Si with a one-proton removal reaction
from 43P projectiles at 81 MeV/nucleon. The measured cross sections to the individual 42Si final
states are compared to calculations that combine eikonal reaction dynamics with these shell-model
nuclear structure overlaps. The differences in the two shell-model descriptions are examined and
linked to predicted low-lying excited 0+ states and shape coexistence. Based on the present data,
which are in better agreement with the SDPF-MU calculations, the state observed at 2150(13) keV
in 42Si is proposed to be the (0+
2) level.
Vaquero V., Jungclaus A., Rodríguez-Sánchezb J.L., Tostevin J.A., Doornenbal P., Wimmer K., Chen S., Nácher E., Sahin E., Shiga Y., Steppenbeck D., Taniuchi R., Xu Z.Y., Ando T., Baba H., Bello Garrote F.L., Franchoo S., Gargano A., Hadynska-Klek K., Kusoglu A., Liu J., Lokotko T., Momiyama S., Motobayashi T., Nagamine S., Nakatsuka N., Niikura M., Orland R., Saito T., Sakurai H., P.A. Söderström P.A., Tveten G.M., Vajta Zs., Yalcinkaya M. (2019) Inclusive cross sections for one- and multi-nucleon removal from Sn, Sb, and Te projectiles beyond the N=82 shell closure,Physics Letters B 795 pp. 356-361 Elsevier
Inclusive one- and multi-nucleon removal cross sections have been measured for several Sn, Sb and Te isotopes just
beyond the N=82 neutron shell closure. The beams were produced in the projectile fission of a 238U beam at the
Radioactive Isotope Beam Factory at RIKEN. The experimental cross sections are compared to predictions from the
most recent version of the Liege intranuclear cascade model. Although the overall agreement is good, severe discrepancies
are observed for the cases of one- and two-neutron removal from 134Sn and 135Sb projectiles and one-proton knockout
from all measured N=84 isotones. These discrepancies, as well as the relevance of quasi-elastic reaction channels to the
one-neutron removal cross sections, are discussed. In addition, the measured inclusive one-proton knockout cross section
for the semi-magic 134Sn projectile is compared to eikonal direct reaction theory calculations to assess if the suppression
factors to these calculated cross sections, deduced from data on reactions of lighter projectile nuclei, are also applicable
to heavy nuclei.
Sword C., Brett J., Baumann T., Brown B.A., Frank N., Herman J., Jones M.D., Karrick H., Kuchera A.N., Thoennessen M., Tostevin J.A., Tuttle-Timm M., DeYoung P.A. (2019) Observation of Three-Neutron Sequential Emission from 25O,Physical Review C 100 034323 pp. 034323-1 - 034323-6 American Physical Society

Background: Measurements of neutron-unbound states can test nuclear models in very neutron-rich
nuclei that in some cases cannot be probed with other methods.

Purpose: Search for highly excited neutron-unbound states of 25O above the three neutron
separation energy.

Method: The decay energy of 25O was reconstructed using the invariant mass spectroscopy
method. A 101.3 MeV/u 27Ne beam collided with a liquid deuterium target. Two-proton removal
reactions populated excited 25O that decayed into three neutrons and an 22O fragment. The
neutrons were detected by arrays of plastic scintillator bars, while a 4 Tm dipole magnet placed
directly after the target redirected charged fragments to a series of charged-particle detectors. The
data were compared with detailed Monte Carlo simulations of the reaction process and subsequent
decay.

Results: The data show evidence of neutron-unbound level(s) in 25O at an excitation energy of
about 9 MeV which decay sequentially by the emission of three neutrons to 22O.

Conclusion: The observation of resonance strength in 25O at about 9 MeV is consistent with
shell-model/eikonal calculations for the two-proton removal reaction from 27Ne.

Elder R., Iwasaki H., Ash J., Bazin D., Bender P. C., Braunroth T., Brown B. A., Campbell C. M., Crawford H. L., Elman B., Gade A., Grinder M., Kobayashi N., Longfellow B., Macchiavelli A. O., Mijatovi? T., Pereira J., Revel A., Rhodes D., Tostevin J. A., Weisshaar D. (2019) Intruder dominance in the 0z‚ state of ³²Mg studied with a novel technique for in-flight decays,Physical Review C 100 (4) 041301(R) pp. 041301-1 American Physical Society
The development of advanced ³-ray tracking arrays allows for a sensitive new technique to investigate elusive states of exotic nuclei with fast rare-isotope beams. By taking advantage of the excellent energy and position resolution of the Gamma-Ray Energy Tracking In-beam Nuclear Array, we developed a novel technique to identify in-flight isomeric decays of the 0z‚ state in 32Mg populated in a two-proton removal reaction. We confirm the 0z‚’2+1³-ray transition of ³²Mg and constrain the 0z‚ decay lifetime, suggesting a large collectivity. The small partial cross section populating the 0z‚ state in this reaction provides experimental evidence for the reduced occupancy of the normal configuration of the 0z‚ state, indicating the intruder dominance of this state.
Spieker M., Weisshaar D., Gade A., Brown B. A., Adrich P., Bazin D., Bentley M.A., Brown J.R., Campbell C.M., Diget C.Aa., Elman B., Glasmacher T., Hill M., Longfellow B., Pritychenko B., Ratkiewicz A., Rhodes D., Tostevin J.A. (2019) Experimental identification of the T = 1, JÀ
= 6+ state of 54Co and isospin symmetry in A = 54 studied via one-nucleon knockout reactions
,
Physical Review C 100 (6) 061303(R) American Physical Society
New experimental data obtained from ³-ray tagged one-neutron and one-proton knockout from 55Co is presented. A candidate for the sought-after T = 1, T z = 0, JÀ
= 6+ state in 54Co is proposed based on a comparison to the new data on 54Fe, the corresponding observables predicted by large-scale-shell-model (LSSM) calculations in the full fp-model space employing charge-dependent contributions, and isospin-symmetry arguments. Furthermore, possible isospin-symmetry breaking in the A = 54, T = 1 triplet is studied by calculating the experimental c coefficients of the isobaric mass multiplet equation (IMME) up to the maximum possible spin J = 6 expected for the (1f7/2)-2 two-hole configuration relative to the doubly-magic nucleus 56Ni. The experimental quantities are compared to the theoretically predicted c coefficients from LSSM calculations using two-body matrix
elements obtained from a realistic chiral effective field theory potential at next-to-next-to-next-to leading order (N3LO).
Ota S., Christian G., Lotay G., Catford W.N, Bennett E.A, Dede S., Doherty Daniel, Hallam Sam, Hooker J., Hunt C., Jayatissa H., Matta A., Moukaddam Mohamad, Rogachev G.V, Saastamoinen A., Tostevin Jeffrey, Upadhyayula S., Wilkinson Ryan (2020) Decay properties of 22Ne + ý resonances and their impact
on s-process nucleosynthesis
,
Physics Letters B 802 135256 Elsevier
The astrophysical s-process is one of the two main processes forming elements heavier
than iron. A key outstanding uncertainty surrounding s-process nucleosynthesis
is the neutron flux generated by the 22Ne(ý; n)25Mg reaction during the He-core and
C-shell burning phases of massive stars. This reaction, as well as the competing
22Ne(ý;)26Mg reaction, is not well constrained in the important temperature regime
from ý0:2?0:4 GK, owing to uncertainties in the nuclear properties of resonances lying
within the Gamow window. To address these uncertainties, we have performed
a new measurement of the 22Ne(6Li; d)26Mg reaction in inverse kinematics, detecting
the outgoing deuterons and 25;26Mg recoils in coincidence. We have established a
new n=
decay branching ratio of 1:14(26) for the key Ex = 11:32 MeV resonance in
26Mg, which results in a new (ý; n) strength for this resonance of 42(11) ýeV when
combined with the well-established (ý;
) strength of this resonance. We have also determined
new upper limits on the ý partial widths of neutron-unbound resonances at
Ex = 11:112; 11:163, 11:169, and 11:171 MeV. Monte-Carlo calculations of the stellar 22Ne(ý; n)25Mg and 22Ne(ý;
)26Mg rates, which incorporate these results, indicate
that both rates are substantially lower than previously thought in the temperature range
from ý0:2?0:4 GK.
Vaquero V., Jungclaus A., Aumann T., Tscheuschner J., Litvinova E. V., Tostevin Jeffrey, Baba H., Ahn D. S., Avigo R., Boretzky K., Bracco A., Caesar C., Camera F., Chen S., Derya V., Doornenbal P., Endres J., Fukuda N., Garg U., Giaz A., Harakeh M. N., Heil M., Horvat A., Ieki K., Imai N., Inabe N., Kalantar-Nayestanaki N., Kobayashi N., Kondo Y., Koyama S., Kubo T., Martel I., Matsushita M., Million B., Motobayashi T., Nakamura T., Nakatsuka N., Nishimura M., Nishimura S., Ota S., Otsu H., Ozaki T., Petri M., Reifarth R., Rodríguez-Sánchez J. L., Rossi D., Saito A. T., Sakurai H., Savran D., Scheit H., Schindler F., Schrock P., Semmler D., Shiga Y., Shikata M., Shimizu Y., Simon H., Steppenbeck D., Suzuki H., Sumikama T., Symochko D., Syndikus I., Takeda H., Takeuchi S., Taniuchi R., Togano Y., Tsubota J., Wang H., Wieland O., Yoneda K., Zenihiro J., Zilges A. (2020) Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus Sn132 and the Position of the 0f5/2 Proton-Hole State in In131.,Physical Review Letters 124 (2) 022501 APS Physics
Spectroscopic factors of neutron-hole and proton-hole states in 131Sn and 131In, respectively, were
measured using one-nucleon removal reactions from doubly magic 132Sn at relativistic energies. For 131In, a
2910(50)-keV ³ ray was observed for the first time and tentatively assigned to a decay from a 5=2? state
at 3275(50) keV to the known 1=2? level at 365 keV. The spectroscopic factors determined for this new
excited state and three other single-hole states provide first evidence for a strong fragmentation of singlehole strength in 131Sn and 131In. The experimental results are compared to theoretical calculations based on
the relativistic particle-vibration coupling
Longfellow B., Gade A., Tostevin Jeffrey, Simpson E.C, Brown B.A, Magilligan A., Bazin D., Bender P.C, Bowry M., Elman B., Lunderberg E., Rhodes D., Speiker M., Weisshaar D., Williams S.J (2020) Two-neutron knockout as a probe of the composition of states in 22Mg, 23Al, and 24Si,Physical Review C 101 (031303) American Physical Society
Simpson and Tostevin proposed that the width and shape of exclusive parallel momentum distributions
of the A
Revel A., Sorlin O., Marques F.M, Kondo Y., Kahlbow J., Nakamura T., Orr N.A, Nowacki F., Tostevin Jeffrey, Yuan C.X, Achouri N.L, Al Falou H., Atar L., Aumann T., Baba H., Boretzky K., Caesar C., Calvet D., Chae H., Chiga N., Corsi A., Crawford H.L, Delaunay F., Delbart A., Deshayes Q., Dombradi Z., Douma C.A, Elekes Z., Fallon P., Gasparic I., Gheller J.M, Gibelin J., Gillibert A., Harakeh M.N, He W., Hirayama A., Hoffman C.R, Holl M., Horvat A., Horvath A., Hwang J.W, Isobe T., Kalantar-Nayestanaki N., Kawase S., Kim S., Kisamori K., Kobayashi T., Korper D., Koyama S., Kuti I., Lapoux V., Lindberg S., Masuoka S., Mayer J., Miki K., Murakami T., Najafi M., Nakano K., Nakatsuka N., Nilsson T., Obertelli A., de Oliviera Santos F., Otsu H., Ozaki T., Panin V., Paschalis S., Rossi D., Saito A.T, Saito T., Sasano M., Sato H., Satou Y., Scheit H., Schindler F., Schrock P., Shikata M., Shimizu Y., Simon H., Sohler D., Stuhl L., Takeuchi S., Tanaka M., Thoennsen M., Tornqvist H., Togano Y., Tomai T., Tscheuschner J., Tsubota J., Uesaka T., Yang Z., Yasuda M., Yoneda K. (2020) Extending the Southern Shore of the Island of Inversion to 28F,Physical Review Letters 124 (15) American Physical Society
Detailed spectroscopy of the neutron-unbound nucleus
28
F
has been performed for the first time following proton/neutron removal from
29
Ne
/
29
F
beams at energies around
230 MeV
/
nucleon
. The invariant-mass spectra were reconstructed for both the
27
F
(
*
)
+
n
and
26
F
(
*
)
+
2
n
coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the
28
F
ground state, with
S
n
(
28
F
)
=
?
199
(
6
)

keV
, while analysis of the
2
n
decay channel allowed a considerably improved
S
n
(
27
F
)
=
1620
(
60
)

keV
to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of
28
F
. Importantly, in the case of the ground state, the reconstructed
27
F
+
n
momentum distribution following neutron removal from
29
F
indicates that it arises mainly from the
1
p
3
/
2

neutron intruder configuration. This demonstrates that the island of inversion around
N
=
20
includes
28
F
, and most probably
29
F
, and suggests that
28
O
is not doubly magic.

Gade A., Weisshaar D., Brown B.A, Tostevin Jeffrey, Bazin D., Brown K., Charity R.J, Farris P.J, Hill M., Li J., Longfellow B., Reviol W., Rhodes D. (2020) In-beam-ray spectroscopy at the proton dripline: 40Sc,Physics Letters B 808 135637 Elsevier
We report on the first in-beam
-ray spectroscopy of the proton-dripline nucleus 40Sc using two-nucleon pickup onto an
intermediate-energy rare-isotope beam of 38Ca. The 9Be(38Ca,40Sc+)X reaction at 60.9 MeV/nucleon mid-target energy selectively populates states in 40Sc for which the transferred proton and neutron couple to high orbital angular momentum. In turn, due
to angular-momentum selection rules in proton emission and the nuclear structure and energetics of 39Ca, such states in 40Sc then exhibit-decay branches although they are well above the proton separation energy. This work uniquely complements results from particle spectroscopy following charge-exchange reactions on 40Ca as well as 40Ti EC/B+ decay which both display very different
selectivities. The population and-ray decay of the previously known first (5-) state at 892 keV and the observation of a new level at 2744 keV are discussed in comparison to the mirror nucleus and shell-model calculations. On the experimental side, this
work shows that high-resolution in-beam
-ray spectroscopy is possible with new generation Ge arrays for reactions induced by rare-isotope beams on the level of a few ýb of cross section.
Jongile S., Lemasson A., Sorlin O., Wiedeking M., Papka P., Bazin D., Borcea C., Borcea R., Gade A., Iwasaki H., Khan E., Lepailleur A., Mutschler A., Nowacki F., Recchia F., Roger T., Rotaru F., Stanoiu M., Stroberg S.R, Tostevin J.A, Vanderbrouck M., Weisshaar D., Wimmer K. (2020) The Structure of ³³Si and the magicity of the N=20 gap at Z=14,Physical Review C 102 (2) 024321 American Physical Society
The structure of
³³Si
was studied by a one-neutron knockout reaction from a
³tSi
beam at 98.5 MeV/u incident on a
9
Be
target. The prompt
³
rays following the de-excitation of
³³Si
were detected using the GRETINA
³
-ray tracking array while the reaction residues were identified on an event-by-event basis in the focal plane of the S800 spectrometer at the National Superconducting Cyclotron Laboratory. The presently derived spectroscopic factor values,
C
2
S
, for the
3
/
2
+
and
1
/
2
+
states, corresponding to a neutron removal from the
0
d
3
/
2

and
1
s
1
/
2

orbitals, agree with shell model calculations and point to a strong
N
=
20
shell closure. Three states arising from the more bound
0
d
5
/
2

orbital are proposed, one of which is unbound by about 930 keV. The sensitivity of this experiment has also confirmed a weak population of
9
/
2
?
and
11
/
2
?
1
,
2

final states, which originate from a higher-order process. This mechanism may also have populated, to some fraction, the
3
/
2
?
and
7
/
2
?
negative-parity states, which hinders a determination of the
C
2
S
values for knockout from the normally unoccupied
1
p
3
/
2

and
0
f
7
/
2

orbits.
Momiyama S., Wimmer K., Bazin D., Belarge J., Bender P., Elman B., Gade A., Kemper K. W., Kitamura N., Longfellow B., Lunderberg E., Niikura M., Ota S., Schrock P., Tostevin J.A., Weisshaar D. (2020) Shell structure of S43 and collapse of the N=28 shell closure,Physical Review C 102 (3) American Physical Society
The single-particle structure of the N = 27 isotones provides insights into the shell evolution of neutron-rich nuclei from the doubly-magic 48Ca toward the drip line. 43S was studied employing the one-neutron knockout reaction from a radioactive 44S beam. Using a combination of prompt and delayed ³-ray spectroscopy the level structure of 43S was clari?ed. Momentum distributions were analyzed and allowed for spin and parity assignments. The deduced spectroscopic factors show that the 44S ground-state con?guration has a strong intruder component. The results were confronted with shell model calculations using two e?ective interactions. General agreement was found between the calculations, but strong population of states originating from the removal of neutrons from the 2p3/2 orbital in the experiment indicates that the breakdown of the N = 28 magic number is more rapid than the theoretical calculations suggest.