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Nuclear Theory·nucl-th

Thursday·December 3, 2020

6 papers—4 primary·2 cross-listed

All6Primary4Cross-lists2
  1. 01

    [Submitted on 2 Dec 2020]

    Compression modulus and symmetry energy of nuclear matter with KIDS density functional

    Hana Gil · Chang Ho Hyun

    Equation of state of dense nuclear matter is explored in the KIDS density functional theory. Parameters of the equation of state which are coefficients of the energy density expanded in powers of where is the nuclear matter density and is its density at saturation are constrained by using both nuclear data and the mass-radius relation of the neutron star determined from the modern astronomy. We find that the combination of both data can reduce the uncertainty in the equation of state parameters significantly. We confirm that the newly constrained parameters reproduce the basic properties of spherical magic nuclei with high accuracy. Neutron drip lines, on the other hand, show non-negligible dependence on the uncertainty of the nuclear symmetry energy.

    Comments:
    13 pages, 3 figures and 2 tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2012.00930 [pdf]
    New Phys.Sae Mulli(2021)·14 citations
  2. 02

    [Submitted on 2 Dec 2020]

    Imaginary Time Mean-Field Method for Collective Tunneling

    Patrick McGlynn · Cedric Simenel

    Background: Quantum tunneling in many-body systems is the subject of many experimental and theoretical studies in fields ranging from cold atoms to nuclear physics. However, theoretical description of quantum tunneling with strongly interacting particles, such as nucleons in atomic nuclei, remains a major challenge in quantum physics. Purpose: An initial-value approach to tunneling accounting for the degrees of freedom of each interacting particle is highly desirable. Methods: Inspired by existing methods to describe instantons with periodic solutions in imaginary time, we investigate the possibility to use an initial value approach to describe tunneling at the mean-field level. Real-time and imaginary-time Hartree dynamics are compared to the exact solution in the case of two particles in a two-well potential. Results: Whereas real-time evolutions exhibit a spurious self-trapping effect preventing tunneling in strongly interacting systems, the imaginary-time-dependent mean-field method predicts tunneling rates in excellent agreement with the exact solution. Conclusions: Being an initial-value method, it could be more suitable than approaches requiring periodic solutions to describe realistic systems such as heavy-ion fusion.

    Comments:
    Accepted for publication in PRC
    Subjects:
    Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
    arXiv:
    2012.00942 [pdf]
    PRC(2020)·7 citations
  3. 03

    [Submitted on 2 Dec 2020]

    Folding-model approach to reaction cross section of He+C scattering at 790 MeV (published in Results in Physics)

    Shingo Tagami · Tomotsugu Wakasa · Maya Takechi · Jun Matsui · Masanobu Yahiro

    Tanihata {\it et al.} determined matter radii for He from interaction cross sections of He+C scattering at 790 MeV per nucleon, using the optical limit of the Glauber model. Lu {\it et al.} determined proton radii for He with the atomic isotope shifts (AIS). We investigate whether the Love-Franey -matrix folding model is good for He+C scattering at 790 MeV per nucleon.

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2012.01063 [pdf]
    2 citations
  4. 04

    [Submitted on 2 Dec 2020]

    Nuclear pasta structures and symmetry energy

    Cheng-Jun Xia · Toshiki Maruyama · Nobutoshi Yasutake · Toshitaka Tatsumi · Ying-Xun Zhang

    In the framework of the relativistic mean field model with Thomas-Fermi approximation, we study the structures of low density nuclear matter in a three-dimensional geometry with reflection symmetry. The numerical accuracy and efficiency are improved by expanding the mean fields according to fast cosine transformation and considering only one octant of the unit cell. The effect of finite cell size is treated carefully by searching for the optimum cell size. Typical pasta structures (droplet, rod, slab, tube, and bubble) arranged in various crystalline configurations are obtained for both fixed proton fractions and -equilibration. It is found that the properties of droplets/bubbles are similar in body-centered cubic (BCC) and face-centered cubic (FCC) lattices, where the FCC lattice generally becomes more stable than BCC lattice as density increases. For the rod/tube phases, the honeycomb lattice is always more stable than the simple one. By introducing an - cross coupling term, we further examine the pasta structures with a smaller slope of symmetry energy MeV, which predicts larger onset densities for core-crust transition and non-spherical nuclei. Such a variation due to the reduction of is expected to have impacts on various properties in neutron stars, supernova dynamics, and binary neutron star mergers.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    2012.01218 [pdf]
    PRC(2021)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE