Dr Alexis Diaz Torres


Senior Lecturer in Theoretical Nuclear Physics
PhD (Justus-Liebig University Giessen, Germany); MSc & BSc (InSTEC in Havana, Cuba)
+44 (0)1483 689855
01 BB 03

Academic and research departments

Department of Physics.

Biography

Areas of specialism

Theoretical Nuclear Physics; Nuclear Structure and Reactions; Computational Physics

University roles and responsibilities

  • Leader of the Math & Physics Programmes
  • Module Leader of Mathematical and Computational Physics (PHY1038)

Research

Research interests

My teaching

Supervision

Postgraduate research supervision

My publications

Highlights

Most of my publications can be downloaded from ResearchGate (https://www.researchgate.net/profile/Alexis_Diaz-Torres2). Please find below some ePrints at Surrey. A complete list of my publications can be found on ORCID (https://orcid.org/0000-0001-6234-9353).

Publications

Diaz-Torres A (2008) Solving the two-center nuclear shell-model problem with arbitrarily oriented deformed potentials, PHYSICAL REVIEW LETTERS 101 (12) ARTN 122501 AMER PHYSICAL SOC
Rafiei R, du Rietz R, Luong DH, Hinde DJ, Dasgupta M, Evers M, Diaz-Torres A (2010) Mechanisms and systematics of breakup in reactions of Be-9 at near-barrier energies, PHYSICAL REVIEW C 81 (2) ARTN 024601 AMER PHYSICAL SOC
Diaz-Torres A (2010) Coupled-channels density-matrix approach to low-energy nuclear collision dynamics: A technique for quantifying quantum decoherence effects on reaction observables, PHYSICAL REVIEW C 82 (5) ARTN 054617 AMER PHYSICAL SOC
Souza FA, Carlin N, Beck C, Keeley N, Diaz-Torres A, Liguori Neto R, Siqueira-Mello C, de Moura MM, Munhoz MG, Oliveira RAN, Del Santo MG, Suaide AAP, Szanto EM, de Toledo AS (2010) Projectile breakup dynamics for Li-6+Co-59: Kinematical analysis of alpha-d coincidences, EUROPEAN PHYSICAL JOURNAL A 44 (2) pp. 181-187 SPRINGER
Diaz-Torres A (2011) PLATYPUS: A code for reaction dynamics of weakly-bound nuclei at near-barrier energies within a classical dynamical model, COMPUTER PHYSICS COMMUNICATIONS 182 (4) pp. 1100-1104 ELSEVIER SCIENCE BV
Thomas RG, Hinde DJ, Duniec D, Zenke F, Dasgupta M, Brown ML, Evers M, Gasques LR, Rodriguez MD, Diaz-Torres A (2008) Entrance channel dependence of quasifission in reactions forming Th-220, PHYSICAL REVIEW C 77 (3) ARTN 034610 AMER PHYSICAL SOC
Hinde DJ, Dasgupta M, Diaz-Torres A, Evers M (2010) Quantum coherence and decoherence in low energy nuclear collisions: from superposition to irreversibility, NUCLEAR PHYSICS A 834 (1-4) pp. 117C-122C ELSEVIER SCIENCE BV
Dasgupta M, Hinde DJ, Diaz-Torres A, Bouriquet B, Low CI, Milburn GJ, Newton JO (2007) Beyond the coherent coupled channels description of nuclear fusion, PHYSICAL REVIEW LETTERS 99 (19) ARTN 192701 AMER PHYSICAL SOC
Gasques LR, Dasgupta M, Hinde DJ, Peatey T, Diaz-Torres A, Newton JO (2006) Isomer ratio measurements as a probe of the dynamics of breakup and incomplete fusion, PHYSICAL REVIEW C 74 (6) ARTN 064615 AMERICAN PHYSICAL SOC
Dasgupta M, Gasques LR, Luong DH, du Rietz R, Rafiei R, Hinde DJ, Lin CJ, Evers M, Diaz-Torres A (2010) Reaction dynamics of weakly bound nuclei at near-barrier energies, NUCLEAR PHYSICS A 834 (1-4) pp. 147C-150C ELSEVIER SCIENCE BV
Luong DH, Dasgupta M, Hinde DJ, du Rietz R, Rafiei R, Lin CJ, Evers M, Diaz-Torres A (2011) Insights into the mechanisms and time-scales of breakup of Li-6,Li-7, PHYSICS LETTERS B 695 (1-4) pp. 105-109 ELSEVIER SCIENCE BV
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
Diaz-Torres A, Gasques LR, Wiescher M (2007) Effects of nuclear molecular configurations on the astrophysical S-factor for O-16+O-16, PHYSICS LETTERS B 652 (5-6) pp. 255-258 ELSEVIER SCIENCE BV
Diaz-Torres A (2010) Absence of decoherence in the complex-potential approach to nuclear scattering, PHYSICAL REVIEW C 81 (4) ARTN 041603 AMER PHYSICAL SOC
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
Diaz-Torres A (2006) Dynamical collective potential energy landscape: Its impact on the competition between fusion and quasi-fission in a heavy fusing system, FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier 853 pp. 225-230 AMER INST PHYSICS
Beck C, Keeley N, Diaz-Torres A (2007) Coupled-channel effects in elastic scattering and near-barrier fusion induced by weakly bound nuclei and exotic halo nuclei, PHYSICAL REVIEW C 75 (5) ARTN 054605 AMERICAN PHYSICAL SOC
Beck C, Keeley N, Diaz-Torres A (2008) Cluster model for near-barrier fusion induced by weakly bound and halo nuclei, FRONTIERS IN NUCLEAR STRUCTURE, ASTROPHYSICS, AND REACTIONS 1012 pp. 233-237 AMER INST PHYSICS
Diaz Torres A, Moro AM (2014) Insights into low-energy elastic scattering of halo nuclei, Physics Letters B 733 pp. 89-92 Elsevier
Recent measurements of low-energy (quasi)elastic-scattering angular distribution of halo nuclei have shown a strong suppression of the Coulomb-nuclear interference peak. Examining the components of the elastic-scattering differential cross sections for 11Be + 64Zn and 6He + 208Pb at energies near the Coulomb barrier, this appears to be caused by a dramatic phase-change (destructive) of the reduced Coulomb-nuclear interference term due to continuum couplings.
Dasgupta M, Hinde DJ, Diaz-Torres A, Luong DH (2009) Towards a Consistent Understanding of Near-barrier Reactions, FUSION 08 1098 pp. 11-17 AMER INST PHYSICS
Diaz Torres A, Adamian GG, Sargsyan VV, Antonenko NV (2014) Energy-shifting formulae yield reliable reaction and capture probabilities, Physics Letters B 739 pp. 348-351 Elsevier
Predictions of energy-shifting formulae for partial reaction and capture probabilities are compared with coupled channels calculations. The quality of the agreement notably improves with increasing mass of the system and/or decreasing mass asymmetry in the heavy-ion collision. The formulae are reliable and useful for circumventing impracticable reaction calculations at low energies.
Beck C, Rowley N, Papka P, Courtin S, Rousseau M, Souza FA, Carlin N, Liguori Neto F, De Moura MM, Del Santo MG, Suade AAI, Munhoz MG, Szanto EM, De Toledo AS, Keeley N, Diaz-Torres A, Hagino K (2011) CLUSTER MODEL FOR REACTIONS INDUCED BY WEAKLY BOUND AND/OR EXOTIC HALO NUCLEI WITH MEDIUM-MASS TARGETS, INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 20 (4) pp. 943-946 WORLD SCIENTIFIC PUBL CO PTE LTD
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
Diaz-Torres A, Gasques LR, Wiescher M (2008) ASTROPHYSICAL S-FACTOR FOR O-16+O-16 WITHIN THE ADIABATIC MOLECULAR PICTURE, INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 17 (10) pp. 2194-2198 WORLD SCIENTIFIC PUBL CO PTE LTD
Diaz-Torres A (2006) Competition between fusion and quasifission in a heavy fusing system: Diffusion of nuclear shapes through a dynamical collective potential energy landscape, PHYSICAL REVIEW C 74 (6) ARTN 064601 AMERICAN PHYSICAL SOC
Souza FA, Carlin N, Beck C, Keeley N, Diaz-Torres A, Liguori Neto R, Siqueira-Mello C, de Moura MM, Munhoz MG, Oliveira RAN, Del Santo MG, Suaide AAP, Szanto EM, de Toledo AS (2010) Li-6 direct breakup lifetimes, NUCLEAR PHYSICS A 834 (1-4) pp. 420C-423C ELSEVIER SCIENCE BV
Beck C, Zafra ASI, Diaz-Torres A, Thompson IJ, Keeley N, Souza FA (2006) Near-barrier fusion induced by stable weakly bound and exotic halo light nuclei, FUSION06: REACTION MECHANISMS AND NUCLEAR STRUCTURE AT THE COULOMB BARRIER 853 pp. 384-389 AMER INST PHYSICS
Hinde DJ, Thomas RG, du Rietz R, Diaz-Torres A, Dasgupta M, Brown ML, Evers M, Gasques LR, Rafiei R, Rodriguez MD (2008) Disentangling effects of nuclear structure in heavy element formation, PHYSICAL REVIEW LETTERS 100 (20) ARTN 202701 AMER PHYSICAL SOC
Beck C, Rowley N, Papka P, Courtin S, Rousseau M, Souza FA, Carlin N, Liguori Neto R, de Moura MM, Del Santo MG, Suaide AAP, Munhoz MG, Szanto EM, de Toledo AS, Keeley N, Diaz-Torres A, Hagino K (2010) Reaction mechanisms for weakly-bound, stable nuclei and unstable, halo nuclei on medium-mass targets, NUCLEAR PHYSICS A 834 (1-4) pp. 440C-445C ELSEVIER SCIENCE BV
Diaz-Torres A (2010) Modelling incomplete fusion dynamics of weakly bound nuclei at near-barrier energies, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS 37 (7) ARTN 075109 IOP PUBLISHING LTD
Hinde DJ, du Rietz R, Thomas RG, Rafiei R, Dasgupta A, Diaz-Torres A (2009) Fission and quasi-fission: insights into heavy element formation reactions, FUSION 08 1098 pp. 281-288 AMER INST PHYSICS
Diaz Torres A (2017) Molecular Structure in Slow Nuclear Collisions, pp. 447-470 World Scientific Publishing
A modern two-center shell model and its usefulness for addressing low-energy reaction dynamics of light and heavy nuclei are presented. A perspective for further developments in nuclear reaction theory is given.
Diaz Torres A (2017) OWL: a code for the two-center shell model with spherical Woods-Saxon potentials, Computer Physics Communications 224 pp. 381-386 Elsevier
A Fortran-90 code for solving the two-center nuclear shell model problem is
presented. The model is based on two spherical Wood-Saxon potentials and
the potential separable expansion method. It describes the single-particle
motion in low-energy nuclear collisions, and is useful for characterizing a
broad range of phenomena from fusion to nuclear molecular structures.
Diaz Torres A, Quraishi D (2018) Effects of unconventional breakup modes on incomplete fusion of weakly bound nuclei, Physical Review C 97 American Physical Society
The incomplete fusion dynamics of 6Li + 209Bi collisions at energies above the Coulomb barrier is investigated. The classical dynamical model implemented in the {\sc platypus} code is used to understand and quantify the impact of both 6Li resonance states and transfer-triggered breakup modes (involving short-lived projectile-like nuclei such as 8Be and 5Li) on the formation of incomplete fusion products. Model calculations explain the experimental incomplete-fusion excitation function fairly well, indicating that (i) delayed direct breakup of 6Li reduces the incomplete fusion cross-sections, and (ii) the neutron-stripping channel practically determines those cross-sections.
Diaz Torres A, Wiescher M (2018) Characterizing the astrophysical S-factor for 12C+12C with
wave-packet dynamics,
Physical Review C 97 (5) pp. 055802-1 - 055802-8 American Physical Society
A quantitative study of the astrophysically important sub-barrier fusion of 12C+12C is presented.
Low-energy collisions are described in the body-fixed reference frame using wave-packet dynamics
within a nuclear molecular picture. A collective Hamiltonian drives the time propagation of the
wave-packet through the collective potential-energy landscape. The fusion imaginary potential for
specific dinuclear configurations is crucial for understanding the appearance of resonances in the
fusion cross section. The theoretical sub-barrier fusion cross sections explain some observed resonant
structures in the astrophysical S-factor. These cross sections monotonically decline towards
stellar energies. The structures in the data that are not explained are possibly due to cluster effects
in the nuclear molecule, which are to be included in the present approach.