PaperPanorama

Nuclear Theory·nucl-th

Thursday·May 9, 2024

12 papers7 primary·5 cross-listed

  1. 01

    [Submitted on 7 May 2024]

    Comment on "Spin-trap isomers in deformed, odd-odd nuclei in the light rare-earth region near "

    M. Stryjczyk · A. Jaries · A. Kankainen · T. Eronen

    A new isomeric state at 285.5(32) keV in Tb was reported by R. Orford et al. [Phys. Rev. C 102, 011303(R) (2020)] based on a Penning-trap mass measurement. Here we show that this result is not compatible with existing experimental data. The state identified as Tb with a mass-excess value of keV is actually the ground state. The state identified as the ground state of Tb is most likely a molecular contaminant with the same mass-over-charge ratio.

    Comments:
    2 pages, 1 figure; comment on https://doi.org/10.1103/PhysRevC.102.011303
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2405.04563 [pdf]
    PRC(2025)·2 citations
  2. 02

    [Submitted on 7 May 2024]

    Inter-band B(E1) Strengths in Heavy Nuclei based on the Proxy-SU(3) Scheme

    Alejandro Restrepo · José P. Valencia

    Rotational bands of positive and negative parity are frequently found experimentally in heavy deformed even-even nuclei along with their corresponding intra-band and inter-band transitions. In symmetry-based models, calculating the strengths is relatively straightforward due to the relation between the operator and the quadrupole generator of the algebra. However, calculating the strengths is a more difficult task, requiring computations involving the shell-model expansion of the dipole operator and multi-shell matrix elements. In this work the operator is expanded in second quantization and applied to calculate the inter-band strengths of the isotope Th using the semi-microscopic algebraic quartet model (SAQM) based on the recently proposed proxy- scheme.

    Comments:
    9 pages, 3 figures. Wigner-Eckart theorem normalization factor corrected. Typo in phase of equations of appendix B. Black and white format friendly graphics
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2405.04679 [pdf]
    PRC(2025)·2 citations
  3. 03

    [Submitted on 8 May 2024]

    Collective-subspace requantization for sub-barrier fusion reactions: Inertial functions for collective motions

    Chisato Ruike · Kai Wen · Nobuo Hinohara · Takashi Nakatsukasa

    The adiabatic self-consistent collective coordinate (ASCC) method is used to determine the optimum reaction path and to calculate the potential and the inertial functions of the reaction model. The properties of the inertial functions are investigated with the ASCC method, in comparison with those of the cranking formulae. In addition, the properties of the pair rotation are investigated in the BCS pair model. The moments of inertia for rotation in both the real and the gauge spaces may decrease as the deformation develops.

    Comments:
    10 pages, Proceedings of FUSION23
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2405.04809 [pdf]
    EPJ Web Conf.(2024)·1 citation
  4. 04

    [Submitted on 8 May 2024]

    Effect of dark matter interaction on hybrid star in the light of the recent astrophysical observations

    Suman Pal🇮🇳 · Gargi Chaudhuri🇮🇳

    We have explored the effect of dark matter interaction on hybrid star (HS) in the light of recent astrophysical observational constraints. The presence of dark matter is assumed to be there in both the hadron as well as the quark sector. The dark matter particle interacts with both hadron and quark matter through the exchange of a scalar as well as a vector meson. The equation of state (EOS) of the hadron part is computed using the NL3 version of the relativistic mean field(RMF) model, whereas the quark part is taken care of using the well-known MIT Bag model with the vector interaction. We investigate the effect of the dark matter density and the mass of the dark matter particle on various observables like mass, radius, tidal deformability of the dark matter admixed hybrid star(DMAHS). In this study, we have noted an intriguing aspect that is the speed of sound in the DMAHS is insensitive to both the mass as well as the density of dark matter. We also observe a striking similarity in the variation of transition mass and its corresponding radius, as well as the maximum mass of neutron stars, with dark matter density and mass. We employ observational constraints from neutron stars to narrow down the allowed range of the parameters of dark matter.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2405.04856 [pdf]
    JCAP(2024)·13 citations
  5. 05

    [Submitted on 8 May 2024]

    Isospin symmetry breaking in atomic nuclei

    J. A. Sheikh · S. P. Rouoof · R. N. Ali · N. Rather · Chandan Sarma · P. C. Srivastava

    The importance of the isospin symmetry and its breaking in elucidating the properties of atomic nuclei is reviewed. The quark mass splitting and the electromagnetic origin of the isospin symmetry breaking (ISB) for nuclear many-body problem is discussed. The experimental data on isobaric analogue states cannot be described only with the Coulomb interaction, and ISB terms in the nucleon-nucleon interaction are needed to discern the observed properties. In the present work, the ISB terms are explicitly considered in nuclear energy density functional and spherical shell model approaches, and a detailed investigation of the analogue states and other properties of nuclei is performed. It is observed that isospin mixing is largest for the system in the density functional approach.

    Comments:
    44 pages, 19 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2405.04946 [pdf]
    Symmetry(2024)·8 citations
  6. 06

    [Submitted on 8 May 2024]

    Formal Theory of Heavy Ion Double Charge Exchange Reactions

    Horst Lenske · Jessica Bellone · Maria Colonna · Danilo Gambacurta · Jose-Antonio Lay

    The theory of heavy ion double charge exchange (DCE) reactions is recapitulated emphasizing the role of Double Single Charge Exchange (DSCE) and pion-nucleon Majorana DCE (MDCE) reactions. DSCE reactions are of second--order distorted wave character, mediated by isovector nucleon-nucleon (NN) interactions. The DSCE response functions resemble the nuclear matrix elements (NME) of decay. The MDCE process proceeds by a dynamically generated effective rank-2 isotensor interaction, defined by off--shell pion--nucleon DCE scattering. In closure approximation pion potentials and two--nucleon correlations are obtained, similar to the neutrino potentials and the intranuclear exchange of Majorana neutrinos in Majorana double beta decay (MDBD).

    Comments:
    8 pages, 6 figures, Contribution to NRM 16, Varenna, JUne 2023
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2405.04978 [pdf]
    EPJ Web Conf.(2024)·3 citations
  7. 07

    [Submitted on 8 May 2024]

    Ab initio computations of strongly deformed nuclei around Zr

    B. S. Hu · Z. H. Sun · G. Hagen · T. Papenbrock

    Nuclei around are strongly deformed and exhibit coexistence of shapes. These phenomena have challenged nuclear models. Here we perform ab initio coupled-cluster computations of low-lying collective states and electromagnetic quadrupole transitions of the even-even nuclei Kr, Sr, Zr and Mo starting from chiral nucleon-nucleon and three-nucleon forces. Our calculations reproduce the coexistence of oblate and prolate shapes in these nuclei, yield rotational bands and strong electromagnetic transitions, but are not accurate for some observables and nuclei. These results highlight the advances and challenges of ab initio computations of heavy deformed nuclei.

    Comments:
    10 pages
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2405.05052 [pdf]
    PRC(2024)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE