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Nuclear Theory·nucl-th

Friday·August 6, 2021

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    [Submitted on 4 Aug 2021]

    Charge radii in covariant density functional theory: a global view

    U. C. Perera · A.V. Afanasjev · P. Ring

    A systematic global investigation of differential charge radii has been performed within the CDFT framework for the first time. Theoretical results obtained with conventional covariant energy density functionals and separable pairing interaction are compared with experimental differential charge radii in the regions of the nuclear chart in which available experimental data crosses neutron shell closures at N = 28, 50, 82 and 126. The analysis of absolute differential radii of different isotopic chains and their relative properties indicate clearly that such properties are reasonably well described in model calculations in the cases when the mean-field approximation is justified. However, while the observed clusterization of differential charge radii of different isotopic chains is well described above the N=50 and N=126 shell closures, it is more difficult to reproduce it above the N=28 and N=82 shell closures because of possible deficiencies in underlying single-particle structure. The impact of the latter has been evaluated for spherical shapes and it was shown that the relative energies of the single-particle states and the patterns of their occupation with increasing neutron number have an appreciable impact on the evolution of the differential charge radii. It is shown that the kinks in the charge radii at neutron shell closures are due to the underlying single-particle structure and due to weakening or collapse of pairing at these closures. It is usually assumed that pairing is a dominant contributor to odd-even staggering (OES) in charge radii. Our analysis paints a more complicated picture. It suggests a new mechanism in which the fragmentation of the single-particle content of the ground state in odd-mass nuclei due to particle-vibration coupling provides a significant contribution to OES in charge radii.

    Comments:
    38 pages, 33 figures, submitted to Physical Review C, supplemental information is provided in the file named "supplemental.pdf". Revised version of the manuscript which takes into account the recommendations of referee
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2108.02245 [pdf]
    PRC(2021)·79 citations
  2. 02

    [Submitted on 5 Aug 2021]

    Elastic -C scattering at low energies with the resonant and states of O

    Shung-Ichi Ando

    The elastic -C scattering for at low energies is studied in an effective Lagrangian approach. We explicitly include two resonant and states of O in the scattering amplitudes and construct an matrix assuming that three amplitudes, the non-resonant part of the amplitude which has the sub-threshold state of O and those of the two resonant states, are represented by the summation of corresponding parts of the phase shift. Then, we fit the parameters in the matrix to the phase shift data by imposing three conditions at very low energies where the phase shift data are not available. By using the fitted parameters, we calculate the asymptotic normalization coefficients (ANC) of the state of O and find that the previously reported small and large values of the ANC can be reproduced depending on the imposed conditions, but we obtain large error bars for the large ANC values which are reported from the transfer reactions.

    Comments:
    17 pages, 6 figures; the version accepted for publication in Phys. Rev. C
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2108.02386 [pdf]
    PRC(2022)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE