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Nuclear Theory·nucl-th

Monday·May 30, 2022

7 papers—3 primary·4 cross-listed

All7Primary3Cross-lists4
  1. 01

    [Submitted on 27 May 2022]

    Two-dimensional extrapolation procedure for ab initio study of nuclear size parameters and the properties of halo nucleus 6He

    D. M. Rodkin · Yu. M. Tchuvil'sky

    A new two-dimensional procedure for extrapolation of the values of matter, neutron, and proton radii obtained in no-core shell model (NCSM) calculations to infinite size of its basis is proposed. A relationship between the radii is used as an additional test. Together with the JISP16 potential, which is frequently used in NCSM calculations of the radii, the Daejeon16 potential is applied for these purposes for the first time. Halo nucleus 6He is the object of studies. The small spread of radii values, successful testing using relationship between the values of these three radii, and reasonable agreement between the obtained results and experimental data as well as the results of other advanced ab initio calculations demonstrate the high efficiency of the developed approach and, therefore, good prospects for its application. The performed investigations and analysis of the results of other studies indicate that the halo of 6He has a large size 0.7 - 0.8 fm.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2205.13798 [pdf]
    PRC(2022)·10 citations
  2. 02

    [Submitted on 27 May 2022]

    Quantum design in study of pycnonuclear reactions in compact stars and new quasibound states

    Sergei P. Maydanyuk (1 and 2)🇭🇺 · Kostiantyn A. Shaulskyi (2) ((1) Wigner Research Center for Physics, Budapest (2) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv)🇺🇦

    Pycnonuclear reactions in the compact stars at zero temperatures are studied on quantum mechanical basis in the paper. Formalism of multiple internal reflections is generalized for analysis, that was developed for nuclear decays and captures by nuclei with high precision and tests. For the chosen reaction C + C = Mg, we find the following. A quantum study of the pycnonuclear reaction requires a complete analysis of quantum fluxes in the internal nuclear region. This reduces rate and number of pycnonuclear reactions by 1.8 times. This leads to the appearance of new states (called as quasibound states) where the compound nuclear system is formed with maximal probability. As shown, minimal energy of such a state is a little higher than energy of zero-point vibrations in lattice sites in pycnonuclear reaction, however probability of formation of compound system at the quasibound state is essentially larger than the corresponding probability at state of zero-point vibrations. Hence, there is a sense to tell about reaction rates in such quasibound states as more probable, rather than states of zero-point vibrations. This can lead to the essential changes in estimation of the rates of nuclear reactions in stars.

    Comments:
    19 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Theory (hep-th)
    arXiv:
    2205.13895 [pdf]
    EPJA(2022)·3 citations
  3. 03

    [Submitted on 27 May 2022]

    Be-nucleus optical potentials developed from chiral effective field theory interactions

    V. Durant · P. Capel

    We present a determination of optical potentials for Be-nucleus collisions using the double-folding method to compute the real part and Kramers-Kronig dispersion relations to derive the imaginary part. As microscopic inputs we use chiral effective field theory nucleon-nucleon interactions at next-to-next-to-leading order combined with state-of-the-art nucleonic densities. With these potentials, we compute elastic scattering cross sections for the exotic nucleus 10 Be off various targets, and compare them to experiment. Without any fitting parameter, we obtain good agreement with data. For collisions on light targets, we observe significant uncertainty related to the short-range physics, whereas for heavy targets that uncertainty remains small.

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2205.13987 [pdf]
    PRC(2022)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE