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Nuclear Theory·nucl-th

Monday·September 28, 2020

12 papers—3 primary·9 cross-listed

All12Primary3Cross-lists9
  1. 01

    [Submitted on 24 Sept 2020]

    Kinetic energy dissipation and fluctuations in strongly-damped heavy-ion collisions within the stochastic mean-field approach

    Sakir Ayik · Kazuyuki Sekizawa

    Background: Microscopic mean-field approaches have been successful in describing the most probable reaction outcomes in low-energy heavy-ion reactions. However, those approaches are known to severely underestimate dispersions of observables around the average values that has limited their applicability. Recently it has been shown that a quantal transport approach based on the stochastic mean-field (SMF) theory significantly improves the description, while its application has been limited so far to fragment mass and charge dispersions. Purpose: In this work, we extend the quantal transport approach based on the SMF theory for relative kinetic energy dissipation and angular momentum transfer in low-energy heavy-ion reactions. Results: As the first application of the proposed formalism, we consider the radial linear momentum dispersion, neglecting the coupling between radial and angular momenta. We analyze the total kinetic energy (TKE) distribution of binary reaction products in the Xe+Pb reaction at MeV and compare with experimental data. From time evolution of single-particle orbitals in TDHF, the radial diffusion coefficient is computed on a microscopic basis, while a phenomenological treatment is introduced for the radial friction coefficient. By solving the quantal diffusion equation for the radial linear momentum, the dispersion of the radial linear momentum is obtained, from which one can construct the TKE distribution. We find that the calculations provide a good description of the TKE distribution for large values of energy losses, TKEL 150 MeV. However, the calculations underestimate the TKE distribution for smaller energy losses. Further studies are needed to improve the technical details of calculations. (Shortened due to the word limit)

    Comments:
    17 pages, 6 figures, 2 tables (plus 5 figures in Appendix); v2 - Version accepted for publication in Physical Review C, with additional analysis on DD-TDHF in Appendix C
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2009.11978 [pdf]
    PRC(2020)·15 citations
  2. 02

    [Submitted on 25 Sept 2020]

    Chiral crossover transition from the Dyson-Schwinger equations in a sphere

    Yin-Zhen Xu🇨🇳 · Chao Shi🇨🇳 · Xiao-Tao He🇨🇳 · Hong-Shi Zong🇨🇳

    Within the framework of Dyson--Schwinger equations of QCD, we study the effect of finite volume on the chiral phase transition in a sphere with the MIT boundary condition. We find that the chiral quark condensate and pseudotransition temperature of the crossover decreases as the volume decreases, until there is no chiral crossover transition at last. We find that the system for \ fm is indistinguishable from fm and there is a significant decrease in with as fm. When fm, there is no chiral transition in the system.

    Comments:
    5 pages, 2 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2009.12035 [pdf]
    PRD(2020)·16 citations
  3. 03

    [Submitted on 25 Sept 2020]

    SWANLOP : Scattering waves off nonlocal optical potentials in the presence of Coulomb interactions

    H. F. Arellano🇨🇱 · G. Blanchon🇫🇷

    We introduce the package SWANLOP to calculate scattering waves and corresponding observables for nucleon elastic collisions off spin-zero nuclei. The code is capable of handling local and nonlocal optical potentials superposed to long-range Coulomb interaction. Solutions to the implied Schrödinger integro-differential equation are obtained by solving an integral equation of Lippmann-Schwinger type for the scattering wavefunctions, , providing and exact treatment to the Coulomb force [Phys. Lett. B 789, 256 (2019)]. The package has been developed to handle potentials either in momentum or coordinate representations, providing flexible options under each of them. The code is fully self-contained, being dimensioned to handle any target for nucleon beam energies of up to 1.1 GeV. Accuracy and benchmark applications are presented and discussed.

    Comments:
    Accepted for publication in Computer Physics Communications. Code available at CPC web site or by request to HFA. PLB page number corrected in Abstract
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2009.12235 [pdf]
    Comput.Phys.Commun.(2021)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE