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Nuclear Theory·nucl-th

Friday·March 29, 2024

10 papers—6 primary·4 cross-listed

All10Primary6Cross-lists4
  1. 01

    [Submitted on 28 Mar 2024]

    Inner fission barriers of uranium isotopes in the deformed relativistic Hartree-Bogoliubov theory in continuum

    Wei Zhang · Jin-Ke Huang · Ting-Ting Sun · Jing Peng · Shuang Quan Zhang

    The inner fission barriers of the even-even uranium isotopes from the proton to the neutron drip line are studied with the deformed relativistic Hartree-Bogoliubov theory in continuum. A periodic evolution for the ground state shapes is shown with the neutron number, i.e., spherical shapes at shell closures 126, 184, 258, and prolate dominated shapes between them. In analogy to the shape evolution, the inner fission barriers also exhibit a periodic behavior: peaks at the shell closures and valleys in the mid-shells. The triaxial effect to the inner fission barrier is evaluated using the triaxial relativistic mean field calculations plus a simple BCS method for pairing. With the triaxial correction included, good consistency in the inner barrier heights is found with the available empirical data. Besides, the evolution from the proton to the neutron drip line is in accord with the results by the multi-dimensionally constrained relativistic mean field theory. A flat valley in the fission barrier height is predicted around the neutron-rich nucleus U which may play a role of fission recycling in the astrophysical -process nucleosynthesis.

    Comments:
    7 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.19092 [pdf]
    CPC(2024)·8 citations
  2. 02

    [Submitted on 28 Mar 2024]

    Algorithm to Obtain Inverse Potentials for Scattering using Variable Phase Approach

    Anil Khachi · Shikha Awasthi · Lalit Kumar · O.S.K.S Sastri

    An algorithm has been developed with the purpose of obtaining inverse potentials, where the Riccati-type non-linear differential equation, also called phase equation, has been kept in tandem with the Variational Monte Carlo method. The optimization of Gaussian function parameters is achieved such that the experimental phase shifts are reproduced. The obtained SPS for various channels has been compared with experimental ones with mean absolute percentage error (MAPE) as a measure. The model parameters have been optimised by suitable optimisation technique by looking for minimum value of MAPE. The results for =0, 2 and 4 partial waves have been obtained, to match with experimental SPS, with MAPE values of , and respectively for data up to MeV, while for higher states 6, 8 and 10 has MAPE of and respectively for data from MeV. On extrapolation for data in range E = MeV, using the optimised parameters, the SPS are found to be in close agreement with experimental ones for the first three channels.

    Comments:
    18 pages, 7 figures, 25 references
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.19173 [pdf]
    Comput.Math.Math.Phys.(2024)·3 citations
  3. 03

    [Submitted on 28 Mar 2024]

    Cross-checking the geometric effects in heavy-ion collisions at 1 GeV/nucleon

    Zu-Xing Yang · Xiao-Hua Fan · Zhi-Pan Li · Shunji Nishimura

    Employing the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, the 1 GeV/nucleon deformed uranium-uranium ultra-central collisions are simulated. Based on sensitive observables, mean square collective flow and pion meson multiplicity, the impacts of high-momentum tails caused by short-range correlations and the symmetry energy in high-density regions on geometric effects are discussed under different reaction orientations. Finally, the neural network model for identifying reaction orientations is also developed.

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2403.19208 [pdf]
    0 citations
  4. 04

    [Submitted on 28 Mar 2024]

    Entanglement in multinucleon transfer reactions

    B. Li · D. Vretenar · T. Nikšić · D. D. Zhang · P. W. Zhao · J. Meng

    Nuclear reactions present an interesting case for studies of the time-evolution of entanglement between complex quantum systems. In this work, the time-dependent nuclear density functional theory is employed to explore entanglement in multinucleon transfer reactions. As an illustrative example, for the reaction Ca Pb at MeV, in the interval of impact parameters fm, and the relativistic density functional PC-PK1, we compute the von Neumann entropies, entanglement between fragments, nucleon-number fluctuations, and Shannon entropy for the nucleon-number observable. A simple linear correlation is established between the entanglement and nucleon-number fluctuation of the final fragments. The entanglement between the fragments can be related to the corresponding excitation energies and angular momenta. The relationship between the von Neumann entropy and the Shannon entropy for the nucleon-number observable is analyzed, as well as the time-evolution of the entanglement (nucleon-number fluctuation). The entanglement is also calculated for a range of incident energies and it is shown how, depending on the impact parameter, the entanglement increases with the collision energy.

    Comments:
    22 pages, 7 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.19288 [pdf]
    PRC(2024)·19 citations
  5. 05

    [Submitted on 28 Mar 2024]

    Bayesian inference of the dense matter equation of state built upon extended Skyrme interactions

    Mikhail V. Beznogov · Adriana R. Raduta

    The non-relativistic model of nuclear matter with Brussels extended Skyrme interactions is employed in order to build, within a Bayesian approach, models for the dense matter equation of state (EOS). In addition to a minimal set of constraints on nuclear empirical parameters; the density behavior of the energy per particle in pure neutron matter (PNM); a lower limit on the maximum neutron star (NS) mass, we require that the Fermi velocity of neutrons () in PNM and symmetric nuclear matter (SNM) with densities up to (arbitrary) does not exceed the speed of light. The latter condition is imposed in order to cure a deficiency present in many Skyrme interactions [Duan and Urban, Phys. Rev. C 108, 025813 (2023)]. We illustrate the importance of this constraint for the posterior distributions. Some of our models are subjected to constraints on the density dependence of neutron (nucleon) Landau effective mass in PNM (SNM), too. The impact of various sets of constraints on the behaviors of nuclear matter and NSs is discussed in detail. Systematic comparison with results previously obtained by employing Skyrme interactions is done for posteriors of both nuclear matter (NM) and NS parameters. Special attention is given to the model and constraints dependence of correlations among various quantities.

    Comments:
    25 pages, 10 figures and 4 tables; Phys. Rev. C, in press
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.19325 [pdf]
    PRC(2024)·18 citations
  6. 06

    [Submitted on 28 Mar 2024]

    Extended Nambu--Jona-Lasinio model for quark and nuclear matters

    Gaoqing Cao🇨🇳

    In this work, we extend the two-flavor Nambu--Jona-Lasinio model to one capable of exploring quark and nuclear matter consistently. With an extra term standing for quark-nucleon interactions, nucleons could automatically emerge as color-singlet three-quark entities by following a process similar to mesons. Besides the quark part in mean field approximation, both mesons and nucleons could contribute to the thermodynamic potential thus possibly give rise to quarkyonic matter beyond mean field. In the study, two kinds of "confining" couplings are adopted for the new interaction term and two different quark masses are considered for comparison. It turns out that only confined nuclear matter or deconfined quark matter is possible for all the cases at zero temperature, thus quarkyonic matter is not favored at all. Even more strictly, only the case with stronger confinement effect and a smaller quark mass admits a physical first-order phase transition from nuclear matter to quark matter around twice saturation density.

    Subjects:
    Nuclear Theory (nucl-th); Superconductivity (cond-mat.supr-con); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2403.19331 [pdf]
    PLB(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE