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Nuclear Theory·nucl-th

Thursday·April 25, 2024

8 papers—6 primary·2 cross-listed

All8Primary6Cross-lists2
  1. 01

    [Submitted on 23 Apr 2024]

    Electromagnetic Form Factors for Nucleons in Short-Range Correlations and the EMC effect

    Dmitriy N. Kim🇺🇸 · Or Hen🇺🇸 · Gerald A. Miller🇺🇸 · E. Piasetzky🇮🇱 · M. Strikman🇺🇸 · L. Weinstein🇺🇸

    The relationship between medium modifications of nucleon electromagnetic form factors and nucleon structure functions is examined using a model motivated by Light-Front Holographic QCD (LFHQCD). These modifications are closely connected with the influence of short-ranged correlations. The size of the modifications to nucleon form factors is shown to be about the same as the modifications to the structure functions. Thus, small limits on form factors modifications do not rule out an explanation of the EMC effect motivated by the influence of short range correlations, as claimed by a recent paper.

    Comments:
    arXiv admin note: text overlap with arXiv:2209.13753, arXiv:2307.15821
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2404.15442 [pdf]
    PRC(2025)·5 citations
  2. 02

    [Submitted on 24 Apr 2024]

    Nuclear incompressibility and its enduring impact on fusion cross-section

    Shilpa Rana · M. Bhuyan · S. K. Patra · Raj Kumar

    The fusion mechanism of reactions involving even-even Sn, doubly magic Sn, Pb as targets, and Ni as the projectile is explored within the relativistic mean field (RMF) formalism. The main aim of choosing these nuclei is to explore the correlation between the nuclear incompressibility and the fusion cross-section. The nucleus-nucleus interaction potential is calculated by folding the axially deformed nuclear densities and the relativistic R3Y nucleon-nucleon (NN) potential obtained for the nonlinear sets of NL3, hybrid, and NL1, which yield different values for various characteristics of nuclear matter at saturation. The fusion barrier characteristics obtained for different RMF parameterizations are further used to calculate the cross-section within the -summed Wong model. We found a decrease in the barrier height and consequently, an increase in the cross-section with a decrease in the incompressibility for all sets of parameters considered. The calculated cross section is satisfactorily consistent with the available experimental data for Ni+Pb system. In contrast, the nuclear potentials obtained for NL3 and the hybrid parameter sets underestimate the cross-section at below-barrier energies for Ni+Sn reactions. This discrepancy between the experimental data and the theoretical results for Ni+Sn reactions can be correlated with the soft behaviour of the Sn isotopes. The compressible nature of Sn-isotopes is inferred to lower the barrier height, which further leads to enhancement of the experimental fusion and/or capture cross-section at below-barrier energies. Thus, the NL1 parameter set with a comparatively soft equation of state (EoS) is observed to be a better choice to describe the sub-barrier nuclear fusion dynamics of reactions involving the Sn-isotopes.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2404.15629 [pdf]
    PRC(2024)·4 citations
  3. 03

    [Submitted on 24 Apr 2024]

    The Coupling Constant of the Pseudovector Pion-nucleon Interaction for the Magnetic Moment of Nucleon

    Susumu Kinpara🇯🇵

    The role of the suppression of the coupling constant in the pseudovector pion-nucleon interaction is examined to account for the calculation of the magnetic moment of nucleon. Among three kinds of the higher-order corrections the vacuum polarization of the pion propagator contributes to the numerical value considerably. On the other hand the lowest-order vertex correction for the pion-nucleon-nucleon vertex does not give large effect in the approximation of the on-shell momenta for nucleons.

    Comments:
    9 pages
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2404.15669 [pdf]
    0 citations
  4. 04

    [Submitted on 24 Apr 2024]

    Primordial Nucleosynthesis with Non-Extensive Statistics

    C.A. Bertulani · Shubhchintak

    The conventional Big Bang model successfully anticipates the initial abundances of 2H(D), 3He, and 4He, aligning remarkably well with observational data. However, a persistent challenge arises in the case of 7Li, where the predicted abundance exceeds observations by a factor of approximately three. Despite numerous efforts employing traditional nuclear physics to address this incongruity over the years, the enigma surrounding the lithium anomaly endures. In this context, we embark on an exploration of Big Bang nucleosynthesis (BBN) of light element abundances with the application of Tsallis non-extensive statistics. A comparison is made between the outcomes obtained by varying the non-extensive parameter q away from its unity value and both observational data and abundance predictions derived from the conventional big bang model. A good agreement is found for the abundances of 4He, 3He and 7Li, implying that the lithium abundance puzzle might be due to a subtle fine-tuning of the physics ingredients used to determine the BBN. However, the deuterium abundance deviates from observations.

    Comments:
    The European Physics Journal, Topical issue "Nuclear Astrophysics: Recent Progress in Understanding Element Formation in the Universe", 19 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
    arXiv:
    2404.15832 [pdf]
    Eur.Phys.J.ST(2024)·2 citations
  5. 05

    [Submitted on 24 Apr 2024]

    Hadronic scattering effects on polarization in relativistic heavy ion collisions

    Haesom Sung🇰🇷 · Che Ming Ko🇺🇸 · Su Houng Lee🇰🇷

    The hyperon spin flip and non-flip cross sections are calculated in a simple hadronic model by including both the -channel process involving the spin 3/2, positive parity resonance and the -channel process via the exchange of a scalar meson. Because of its large mass, the spin flip to non-flip cross sections is negligibly small in the -channel process compared to the constant value of 1/3.5 in the -channel process. With the channel spin-dependent cross sections included in a schematic kinetic model, the effects of hadronic scatterings on the spin polarization in Au-Au collisions at GeV are studied. It is found that the spin polarization only decreases by 7-12\% during the hadronic stage of these collisions, which justifies the assumption in theoretical studies that compare the polarization calculated at the chemical freezeout to the measured one at the kinetic freezeout.

    Comments:
    7 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2404.15890 [pdf]
    PLB(2024)·8 citations
  6. 06

    [Submitted on 24 Apr 2024]

    Calculations of bound-state -decay half-lives of highly ionized Dy, Re and Tl

    Yang Xiao · Long-Jun Wang

    We propose a theoretical method to calculate the bound-state -decay half-lives of highly-ionized atoms, which is based on the combination of the Takahashi-Yokoi model and our recently-developed projected shell model that can take into account both allowed and first-forbidden transitions of nuclear decay. Three examples that are of much experimental interests, Dy, Re and Tl are taken for calculations. The ground and low-lying states of related nuclei are described reasonably. The bound-state -decay half-lives of Dy and Re are described within a factor of two and four by our calculations without and with the quenching factors in allowed and first-forbidden transitions. The bound-state -decay half-life of the last -process branching point Tl is predicted to be 58 and 305 days for cases without and with the quenching factors in calculations. The presented method provides a theoretical way to calculate systematically the bound-state -decay half-lives of nuclei from light to heavy ones including odd-mass and even-mass cases for the first time.

    Comments:
    8 pages, 6 figures, 2 tables, Comments and criticisms are welcome
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2404.15897 [pdf]
    PRC(2024)·6 citations

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first authorsco-authorsvia INSPIRE