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Nuclear Theory·nucl-th

Wednesday·November 2, 2022

6 papers—4 primary·2 cross-listed

All6Primary4Cross-lists2
  1. 01

    [Submitted on 31 Oct 2022]

    New developments in fission studies within the time-dependent density functional theory framework

    Aurel Bulgac

    We have extended significantly the microscopic description of the fission process by examining a larger set of observables. We extract neutron and proton numbers of fission fragments, their spins and fission fragment relative orbital angular momentum and their correlations, investigate neutrons emitted at or shortly after scission, excitation energy sharing mechanism, total kinetic energy of fission fragments, and the entanglement entropy. I will present a short overview of our simulations obtained with two independent nuclear energy density functionals.

    Comments:
    8 pages, 7 figures, prepared for the proceedings of 15th International Conference on Nuclear Data for Science and Technology (ND2022), July 24-29, 2022, published version
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2211.00197 [pdf]
    EPJ Web Conf.(2023)·6 citations
  2. 02

    [Submitted on 1 Nov 2022]

    Microscopic formulation of the interacting boson model for reflection asymmetric nuclei

    Kosuke Nomura

    Reflection asymmetric, octupole shapes in nuclei are a prominent aspect of nuclear structure, and have been recurrently studied over the decades. Recent experiments using radioactive-ion beams have provided evidence for stable octupole shapes. A variety of nuclear models have been employed for the related theoretical analyses. We review recent studies on the nuclear octupole shapes and collective excitations within the interacting boson model. A special focus is placed on the microscopic formulation of this model by using the mean-field method that is based on the framework of nuclear density functional theory. As an illustrative example, a stable octupole deformation, and a shape phase transition as a function of nucleon number that involves both quadrupole and octupole degrees of freedom are shown to occur in light actinides. Systematic spectroscopic studies indicate enhancement of the octupole collectivity in a wide mass region. Couplings between the octupole and additional degrees of freedom are incorporated in a microscopic manner in the boson system, and shown to play a crucial role in the description of the related intriguing nuclear structure phenomena such as the shape coexistence.

    Comments:
    20 pages, 12 figures; Invited contribution submitted to the Special Issue "Reflection Asymmetry in Atomic Nuclei" in Int. J. Mod. Phys. E
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2211.00279 [pdf]
    IJMPE(2023)·6 citations
  3. 03

    [Submitted on 1 Nov 2022]

    Ab initio no-core shell model description of C isotopes

    Priyanka Choudhary · Praveen C. Srivastava · Michael Gennari · Petr Navratil

    We present a systematic study of the isotopes within the \textit{ab initio} no-core shell model theory. We apply four different realistic nucleon-nucleon (NN) interactions: (i) the charge-dependent Bonn 2000 (CDB2K) potential (ii) the inside non-local outside Yukawa (INOY) potential (iii) the next-to-next-to-next-to-leading order (NLO) potential, and (iv) the optimized next-to-next-to-leading order (NLO) potential. We report the low-lying energy spectra of both positive and negative parity states for the isotopes and investigate the level structures. We also calculate electromagnetic properties such as transition strengths, quadrupole and magnetic moments. The dependence of point-proton radii on the harmonic oscillator frequency and basis space is shown. We present calculations of the translation invariant one-body density matrix in the no-core shell model and discuss isotopic trends in the density distribution. The maximum basis space reached is for and for , with a maximum M-scheme dimension of for . We found that while the INOY interaction gives the best description of the ground state energies, the NLO interaction best reproduces the point-proton radii.

    Comments:
    21 pages, 12 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2211.00281 [pdf]
    PRC(2023)·19 citations
  4. 04

    [Submitted on 1 Nov 2022]

    Efficient few-body calculations in finite volume

    S. König🇺🇸

    Simulating quantum systems in a finite volume is a powerful theoretical tool to extract information about them. Real-world properties of the system are encoded in how its discrete energy levels change with the size of the volume. This approach is relevant not only for nuclear physics, where lattice methods for few- and many-nucleon states complement phenomenological shell-model descriptions and ab initio calculations of atomic nuclei based on harmonic oscillator expansions, but also for other fields such as simulations of cold atomic systems. This contribution presents recent progress concerning finite-volume simulations of few-body systems. In particular, it discusses details regarding the efficient numerical implementation of separable interactions and it presents eigenvector continuation as a method for performing robust and efficient volume extrapolations.

    Comments:
    9 pages, 2 figures, ISS 2022 contribution
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2211.00395 [pdf]
    J.Phys.Conf.Ser.(2023)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE