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Nuclear Theory·nucl-th

Thursday·September 2, 2021

10 papers—3 primary·7 cross-listed

All10Primary3Cross-lists7
  1. 01

    Effect of tensor force on lowering of 5/2 level in heavier Cu isotopes

    Kanhaiya Jha · P. K. Raina

    The inversion of 3/2 and 5/2 levels in heavier Cu isotopes is one of the most visible example of shell-evolution, caused by the strong monopole attraction between the nucleons occupying the orbitals and . The tensor part of the nucleon-nucleon interaction is expected to be the driving force behind this monopole migration. In shell model framework, usually spin-tensor decomposition is used to get the information of individual force components to the shell evolution, however, in the present scenario, this method can not apply on \textit{pfg} model space due to the missing spin-orbit partners and . Therefore, we have analytically obtained the tensor force two-body matrix elements (TBMEs) for this model space using Yukawa potential, and subtract it from effective interaction jj44b \cite{}. The interaction without tensor part, named as jj44a, have been used for calculation of Ni, Zn, Ge and Cu isotopes with various physics viewpoints. In most of the cases, the theoretical results are in good agreement with the experiment only when tensor force is included to the interaction jj44a.

    nucl-th0 citations
  2. 02

    Ab initio structure factors for spin-dependent dark matter direct detection

    B. S. Hu🇨🇦 · J. Padua-Argüelles🇨🇦 · S. Leutheusser🇨🇦 · T. Miyagi🇨🇦 · S. R. Stroberg🇺🇸 · J. D. Holt🇨🇦

    We present converged ab initio calculations of structure factors for elastic spin-dependent WIMP scattering off all nuclei used in dark matter direct-detection searches: F, Na, Al, Si, Ge, I, and Xe. From a set of established two- and three-nucleon interactions derived within chiral effective field theory, we construct consistent WIMP-nucleon currents at the one-body level, including effects from axial-vector two-body currents. We then apply the in-medium similarity renormalization group to construct effective valence-space Hamiltonians and consistently transformed operators of nuclear responses. Combining the recent advances of natural orbitals with three-nucleon forces expressed in large spaces, we obtain basis-space converged structure factors even in heavy nuclei. Generally results are consistent with previous calculations, but large uncertainties in I highlight the need for further study.

    nucl-thastro-ph.COhep-exhep-ph+1PRL(2022)·47 citations
  3. 03

    EoS for hot neutron stars

    Adriana R. Raduta🇷🇴 · Flavia Nacu🇷🇴 · Micaela Oertel🇫🇷

    We review the equation of state (EoS) models covering a large range of temperatures, baryon number densities and electron fractions presently available on the \textsc{CompOSE} database. These models are intended to be directly usable within numerical simulations of core-collapse supernovae, binary neutron star mergers and proto-neutron star evolution. We discuss their compliance with existing constraints from astrophysical observations and nuclear data. For a selection of purely nucleonic models in reasonable agreement with the above constraints, after discussing the properties of cold matter, we review thermal properties for thermodynamic conditions relevant for core-collapse supernovae and binary neutron star mergers. We find that the latter are strongly influenced by the density dependence of the nucleon effective mass. The selected bunch of models is used to investigate the EoS dependence of hot star properties, where entropy per baryon and electron fraction profiles are inspired from proto-neutron star evolution. The -law analytical thermal EoS used in many simulations is found not to describe well these thermal properties of the EoS. However, it may offer a fair description of the structure of hot stars whenever thermal effects on the baryonic part are small, as shown here for proto-neutron stars starting from several seconds after bounce.

    nucl-thastro-ph.HEEPJA(2021)·51 citations

Affiliations

first authorsco-authorsvia INSPIRE