PaperPanorama
FAQ

Nuclear Theory·nucl-th

Friday·April 5, 2024

8 papers—5 primary·3 cross-listed

All8Primary5Cross-lists3
  1. 01

    [Submitted on 3 Apr 2024]

    Ab initio leading order effective potential for elastic proton scattering based on the symmetry-adapted no-core shell model

    R.B. Baker · Ch. Elster · T. Dytrych · K.D. Launey

    Based on the Watson expansion of the multiple scattering series, we employ a nonlocal translationally invariant nuclear density derived within the symmetry-adapted no-core shell model (SA-NCSM) framework from a chiral next-to-next-to-leading order (NNLO) nucleon-nucleon interaction and the very same interaction for a consistent full-folding calculation of the effective (optical) potential for nucleon-nucleus scattering for medium-heavy nuclei. The leading order effective (optical) folding potential is computed by integrating over a translationally invariant SA-NCSM one-body scalar density, spin-projected momentum distribution, and the Wolfenstein amplitudes , , and . The resulting nonlocal potentials serve as input for a momentum space Lippmann-Schwinger equation, whose solutions are summed up to obtain nucleon-nucleus scattering observables. In the SA-NCSM, the model space is systematically up-selected using symmetry considerations. For the light nucleus of He, we establish a systematic selection scheme in the SA-NCSM for scattering observables. Then, we apply this scheme to calculations of scattering observables, such as differential cross sections, analyzing powers, and spin rotation functions for elastic proton scattering from Ne and Ca in the energy regime between 65 and 200 MeV, and compare to available data. Our calculations show that the leading order effective nucleon-nucleus potential in the Watson expansion of multiple scattering theory obtained from an up-selected SA-NCSM model space describes Ca elastic scattering observables reasonably well to about 60 degrees in the center-of-mass frame, which coincides roughly with the validity of the NNLO chiral interaction used to calculate both the nucleon-nucleon amplitudes and the one-body scalar and spin nuclear densities.

    Comments:
    8 pages, 1 table, 8 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2404.03106 [pdf]
    PRC(2024)·14 citations
  2. 02

    [Submitted on 4 Apr 2024]

    Neutrino mean free path in neutron stars in the presence of hyperons

    Jesper Leong🇦🇺 · Parada T. P. Hutauruk🇰🇷 · Anthony W. Thomas🇦🇺

    We investigate the neutrino elastic differential cross-section (NDCS) and corresponding mean free path for neutral current scattering in the dense matter of a neutron star. A wide range of observed neutron star (NS) masses is considered, including the presence of , , and hyperons in the heaviest stars. Their presence significantly decreases the total neutrino mean free path in the heavier stars.

    Comments:
    14 pages, 7 figures, 1 table, PRC published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2404.03213 [pdf]
    PRC(2024)·0 citations
  3. 03

    [Submitted on 4 Apr 2024]

    Information entropy for central Au+Au collisions with the ultrarelativistic quantum molecular dynamics model

    Xian-Gai Deng🇨🇳 · Yu-Gang Ma🇨🇳

    This study investigates the multiplicity information entropy of hadrons, anti-hadrons, baryons, and net-protons in central \(^{197}\)Au+\(^{197}\)Au collisions with impact parameters of 03 fm, using the ultrarelativistic quantum molecular dynamics model (UrQMD) across various center-of-mass energies (\(\sqrt{s_{\rm NN}}\)) from 5.0 to 54.4 GeV. Our simulations employ hydrodynamic modes with different equations of state (EoS) and a default mode without hydrodynamics. The results reveal that the information entropies of baryons and net-protons are sensitive to the selected EoS. In particular, enhancements of the information entropies around \(\sqrt{s_{\rm NN}} \sim 30\) GeV, especially with chiral hadron gas and Bag model EoS, indicate a phase transition or critical endpoint behavior. These findings highlight the importance of the EoS in understanding the thermodynamic properties of matter produced in high-energy collisions.

    Comments:
    8 pages, 8 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2404.03424 [pdf]
    PRC(2025)·4 citations
  4. 04

    [Submitted on 4 Apr 2024]

    Radiative corrections to the spin asymmetry in elastic polarized electron-nucleus collisions at high energy

    D.H.Jakubassa-Amundsen

    Modifying the numerical codes, dispersion corrections to the beam-normal spin asymmetry which arise from low-lying transient nuclear excitations up to 30 MeV, are estimated for collision energies between 50 MeV and 1 GeV. A nonperturbative calculation of vacuum polarization and the vertex plus self-energy correction, using optimized potentials, indicates that for small scattering angles both these quantum electrodynamical (QED) effects on the spin asymmetry decrease with energy above 200 MeV and can be neglected at high energies. Examples are given for the 12C and 208Pb nuclei. The available measurements of the spin asymmetry at collision energies beyond 500 MeV cannot be explained by the present theory.

    Comments:
    12 pages, 10 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2404.03445 [pdf]
    2 citations
  5. 05

    [Submitted on 4 Apr 2024]

    Nuclear Matter Equation of State in the Brueckner-Hartree-Fock Approach and Standard Skyrme Energy-Density Functionals

    Isaac Vidaña🇮🇹 · Jérôme Margueron🇫🇷 · Hans-Josef Schulze🇮🇹

    The equation of state of asymmetric nuclear matter as well as the neutron and proton effective masses and their partial-wave and spin-isospin decomposition are analyzed within the Brueckner--Hartree--Fock approach. Theoretical uncertainties for all these quantities are estimated by using several phase-shift-equivalent nucleon-nucleon forces together with two types of three-nucleon forces, phenomenological and microscopic. It is shown that the choice of the three-nucleon force plays an important role above saturation density, leading to different density dependencies of the energy per particle. These results are compared to the standard form of the Skyrme energy-density functional and we find that it is not possible to reproduce the BHF predictions in the channels in symmetric and neutron matter above saturation density, already at the level of the two-body interaction, and even more including the three-body interaction.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    2404.03583 [pdf]
    Universe(2024)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE