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Nuclear Theory·nucl-th

Friday·April 21, 2023

15 papers—5 primary·10 cross-listed

All15Primary5Cross-lists10
  1. 01

    [Submitted on 20 Apr 2023]

    Improving nuclear data evaluations with predictive reaction theory and indirect measurements

    Jutta Escher🇺🇸 · Kirana Bergstrom🇺🇸 · Emanuel Chimanski🇺🇸 · Oliver Gorton🇺🇸 · Eun Jin In🇺🇸 · Michael Kruse🇺🇸 · Sophie Péru🇫🇷 · Cole Pruitt🇺🇸 · Rida Rahman🇺🇸 · Emily Shinkle🇺🇸 · Aaina Thapa🇺🇸 · Walid Younes🇺🇸

    Nuclear reaction data required for astrophysics and applications is incomplete, as not all nuclear reactions can be measured or reliably predicted. Neutron-induced reactions involving unstable targets are particularly challenging, but often critical for simulations. In response to this need, indirect approaches, such as the surrogate reaction method, have been developed. Nuclear theory is key to extract reliable cross sections from such indirect measurements. We describe ongoing efforts to expand the theoretical capabilities that enable surrogate reaction measurements. We focus on microscopic predictions for charged-particle inelastic scattering, uncertainty-quantified optical nucleon-nucleus models, and neural-network enhanced parameter inference.

    Comments:
    4 pages, 4 figures, proceedings contribution for Nuclear Data 2022
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2304.10034 [pdf]
    EPJ Web Conf.(2023)·2 citations
  2. 02

    [Submitted on 20 Apr 2023]

    Probing the nucleon effective mass splitting with the light particle emission

    Fang-Yuan Wang · Jun-Ping Yang · Xiang Chen · Ying Cui · Yong-Jia Wang · Zhi-Gang Xiao · Zhu-Xia Li · Ying-Xun Zhang

    In this work, we first analyze the correlations among different nuclear matter parameters which are obtained by the 119 effective Skyrme interaction sets. The values of the correlation coefficients illustrate that the magnitude of the effective mass splitting is crucial for the tight constraints of the symmetry energy via HICs. Thus, the main object of this work is to investigate the impacts of the effective mass splitting on the heavy ion collisions observables. The Kr+Pb system at the beam energy ranging from 25A MeV to 200A MeV are simulated within the framework of the improved quantum molecular dynamics model (ImQMD-Sky) for this goal. Our calculations show that the slopes of the spectra of [Y(n)/Y(p)] and [Y(t)/Y(He)], which are the logarithms of the neutron to proton yield ratios and triton to Helium-3 yield ratios, are directly related to the effective mass splitting and can be used to probe the effective mass splitting.

    Comments:
    9 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2304.10171 [pdf]
    Nucl.Sci.Tech.(2023)·15 citations
  3. 03

    [Submitted on 20 Apr 2023]

    Study of S, Cl and Ar isotopes with using microscopic effective -shell interactions

    Priyanka Choudhary · Praveen C. Srivastava

    In the present work, newly developed microscopic effective -valence shell interactions such as chiral next-to-next-to-next-to-leading order (N3LO), -matrix inverse scattering potential (JISP16), Daejeon16 (DJ16), and monopole-modified DJ16 (DJ16A) are employed to study the nuclear structural properties of sulphur, chlorine, and argon isotopes with . These interactions are derived using the \textit{ab initio} no-core shell-model and the OLS unitary transformation method. We calculate energy spectra and electromagnetic properties to test the predictive strength of the effective interactions for these heavier -shell nuclei. For a complete systematic study, we compare the microscopic results with the phenomenological USDB results and experimental data. By looking at the excitation energies of these nuclei, the DJ16A interaction is found to be {the} most suitable for these -shell nuclei among all microscopic interactions. The electric quadrupole transition strength and excitation energy of the first state data of even-even sulphur isotopes indicate the presence of the shell closure. Quadrupole moment predictions are also made using these interactions where experimental data are unknown. Magnetic moments are in excellent agreement with the experimental values. The root-mean-square deviations are also calculated to provide an idea of how accurate the interactions are.

    Comments:
    14 pages, 7 figures, The European Physical Journal A-Hadrons and Nuclei (accepted)
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2304.10361 [pdf]
    EPJA(2023)·6 citations
  4. 04

    [Submitted on 20 Apr 2023]

    Self-consistent calculations for atomic electron capture

    V. A. Sevestrean · O. Niţescu · S. Ghinescu · S. Stoica

    We present a comprehensive investigation of electron capture (EC) ratios spanning a broad range of atomic numbers. The study employs a self-consistent computational method that incorporates electron screening, electron correlations, overlap and exchange corrections, as well as shake-up and shake-off atomic effects. The electronic wave functions are computed with the Dirac-Hartree-Fock-Slater (DHFS) method, chosen following a systematic comparison of binding energies, atomic relaxation energies and Coulomb amplitudes against other existing methods and experimental data. A novel feature in the calculations is the use of an energy balance employing atomic masses, which avoids approximating the electron total binding energy and allows a more precise determination of the neutrino energy. This leads to a better agreement of our predictions for capture ratios in comparison with the experimental ones, especially for low-energy transitions. We expand the assessment of EC observables uncertainties by incorporating atomic relaxation energy uncertainties, in contrast to previous studies focusing only on Q-value and nuclear level energies. Detailed results are presented for nuclei of practical interest in both nuclear medicine and exotic physics searches involving liquid Xenon detectors (, , , and ). Our study can be relevant for astrophysical, nuclear, and medical applications.

    Comments:
    16 pages, 9 figures, 4 tables
    Subjects:
    Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2304.10373 [pdf]
    PRA(2023)·12 citations
  5. 05

    [Submitted on 19 Apr 2023]

    Real and Imaginary Phase Shifts for Nucleon-Deuteron Scattering using Phase Function Method

    Shikha Awasthi · O. S. K. S. Sastri

    The neutron-deuteron (nd) and proton-deuteron (pd) scattering are the simplest nucleon-nucleus scenario which throws light on understanding few body systems. In this work, real and imaginary parts of scattering phase shifts (SPS) for nd and pd scattering are obtained using optical potential, with Malfliet-Tjon (MT) model of interaction, by phase function method (PFM). The SPS for doublet 2S1/2 and quartet 4S3/2 states of nd and pd systems have been obtained for real and imaginary parts separately by solving the phase equation for l= 0, using Runge-Kutta 5 th order technique for laboratory energies up to 19 M eV . The obtained (real,imaginary) SPS for 2S1/2 and 4S3/2 states are matching with standard data with mean absolute error (MAE) of (1.32, 0.06) for 2S1/2 state and (0.19, 0.06) for 4S3/2 state of nd scattering, (1.47,0.62) for 2S1/2 state and (0.55, 0.14) for 4S3/2 state of pd scattering.

    Comments:
    13 pages, 4 Figures and 3 Tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2304.10478 [pdf]
    Phys.Atom.Nucl.(2024)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE