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Nuclear Theory·nucl-th

Wednesday·June 15, 2022

5 papers—2 primary·3 cross-listed

All5Primary2Cross-lists3
  1. 01

    [Submitted on 14 Jun 2022]

    Implications of parity-violating electron scattering experiments on Ca (CREX) and Pb (PREX-II) for nuclear energy density functionals

    Esra Yüksel🇹🇷 · Nils Paar🇭🇷

    Recent precise parity-violating electron scattering experiments on Ca (CREX) and Pb (PREX-II) provide a new insight on the formation of neutron skin in nuclei. Within the energy density functional (EDF) framework, we investigate the implications of CREX and PREX-II data on nuclear matter symmetry energy and isovector properties of finite nuclei: neutron skin thickness and dipole polarizability. The weak-charge form factors from the CREX and PREX-II experiments are employed directly in constraining the relativistic density-dependent point coupling EDFs. The EDF established with the CREX data acquires considerably smaller values of the symmetry energy parameters, neutron skin thickness and dipole polarizability both for Ca and Pb, in comparison to the EDF obtained using the PREX-II data, and previously established EDFs. Presented analysis shows that CREX and PREX-II experiments could not provide consistent constraints for the isovector sector of the EDFs, and further theoretical and experimental studies are required.

    Comments:
    8 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2206.06527 [pdf]
    PLB(2023)·56 citations
  2. 02

    [Submitted on 14 Jun 2022]

    Impact of fragment formation on shear viscosity in the nuclear liquid-gas phase transition region

    X. G. Den · P. Danielewicz · Y. G. Ma · H. Lin · Y. X. Zhang

    Within the improved quantum molecular dynamic (ImQMD) model we follow the evolution of nuclear matter for planar Couette flow in a periodic box. We focus on the region of liquid-gas phase transition and extract the shear viscosity coefficient from the local stress tensor, directly following viscosity definition. By switching on and off the mean field and thus inducing the phase transition, we are able to observe the impact of clumping in the phase-transition region onto the viscosity.

    Comments:
    10 pages, 9 figures, 2 tables; Physical Review C, in press
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2206.06540 [pdf]
    PRC(2022)·19 citations
  3. 03

    [Submitted on 13 Jun 2022] (cross-list from nucl-ex)

    Proton and neutron exchange as a prelude to fusion at near-barrier energies

    J.E. Johnstone🇺🇸 · Varinderjit Singh🇺🇸 · R. Giri🇺🇸 · S. Hudan🇺🇸 · J. Vadas🇺🇸 · R.T. deSouza🇺🇸 · D. Ackermann🇫🇷 · A. Chbihi🇫🇷 · Q. Hourdille🇫🇷 · A. Abbott🇺🇸 · C. Balhoff🇺🇸 · A. Hannaman🇺🇸 and 11 other authors

    Systematic examination of fusion for K + Si and Ar + Si provides insight into the impact of neutron and proton exchange on fusion for nuclei at and near the N=20 and N=28 shells. Comparison of the reduced excitation functions reveals a marked difference between the behavior of open-shell and closed-shell systems. While coupled channels calculations provide a good description for the closed-shell nuclei they significantly under-predict the fusion cross-section for open-shell nuclei. The observed trends are examined in the context of a potential energy surface, including shell effects, and multi-nucleon exchange with consideration of Pauli-blocking.

    Comments:
    7 pages, 4 figures
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2206.06436 [pdf]
    PRC(2022)·4 citations
  4. 04

    [Submitted on 14 Jun 2022] (cross-list from hep-ph)

    Relations for low-energy coupling constants in baryon chiral perturbation theory derived from the chiral quark model

    Jun Jiang🇨🇳 · Shao-Zhou Jiang🇨🇳 · Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Zong-Guo Si🇨🇳 · Hong-Qian Wang🇨🇳

    The quark model symmetry can be adopted to establish relations between the low-energy constants (LECs) in the baryon chiral perturbation theory () if one assumes that a baryon-baryon-meson coupling is described equivalently by a quark-quark-meson coupling at the quark level. Through the correspondence between the description and the description for the same coupling vertex at the quark level, we find some relations between the LECs in and up to the third chiral order. The LEC relations at the same order are also obtained. The numerical analysis roughly supports these relations. In the situation that the available experimental data are not enough, one may employ such constraints to reduce the number of LECs.

    Comments:
    Version to appear in PRD. 16 pages, 2 figures, 7 tables
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2206.06570 [pdf]
    PRD(2022)·4 citations
  5. 05

    [Submitted on 14 Jun 2022] (cross-list from hep-ph)

    On Ambiguity of Definition of Shear and Spin-Hall Contributions to Polarization in Heavy-Ion Collisions

    Yu. B. Ivanov🇷🇺 · A. A. Soldatov🇷🇺

    Recently proposed thermal-shear and spin-Hall contributions to the particle polarization in heavy-ion collisions are discussed. Alternative definitions of the thermal-shear contribution, i.e. those of Becattini-Buzzegoli-Palermo on the one hand and Liu-Yin on the other, are very similar in the midrapidity region while quite different at forward-backward rapidities, which are measured in fixed-target experiments. It is shown that the thermal-shear contribution to the global polarization with momentum averaging extended to all momenta is very different within these alternative definitions. The spin-Hall contribution to the global polarization, defined similarly to the Liu-Yin shear one, is identically zero, if averaging runs over all momenta. Only application of restrictive momentum acceptance and the boost (to rest frame) correction result in nonzero global spin-Hall polarization. If the spin-Hall contribution were defined similarly to Becattini-Buzzegoli-Palermo shear one, the global spin-Hall polarization would be non-zero even without any acceptance and the boost correction.

    Comments:
    3 pages, version accepted by JETP Letters, minor changes in text and references
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2206.06927 [pdf]
    Pisma Zh.Eksp.Teor.Fiz.(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE