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Nuclear Theory·nucl-th

Thursday·July 25, 2019

5 papers—2 primary·3 cross-listed

All5Primary2Cross-lists3
  1. 01

    [Submitted on 24 Jul 2019]

    -wave quasiparticle resonance in neutron-rich drip-line nuclei

    Yoshihiko Kobayashi · Masayuki Matsuo

    We investigate unbound single-particle states in pair-correlated drip-line nuclei by describing a low-energy elastic scattering of a neutron in the -wave within the framework of the coordinate space Hartree-Fock-Bogolibov (Bogoliubov-de Genne) equation. Numerical study is performed for a neutron drip-line carbon isotope where the neutron orbit is located close to zero energy. Analyzing the S-matrix poles of the elastic scattering, we discuss properties of the -wave quasiparticle resonance and, in particular, behaviors characteristic to drip-line nuclei. It is found that the S-matrix has two pairs of poles; one pair appears as either a weakly bound state, a virtual state or a resonance while the other pair gives contribution analogous to a bound single-particle state. The -wave quasiparticle resonance emerges with a large variation depending on the pairing gap and the single-particle energy of the -orbit.

    Comments:
    33 pages, 17 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1907.10325 [pdf]
    PTEP(2020)·5 citations
  2. 02

    [Submitted on 24 Jul 2019]

    Towards a consistent understanding of the exotic nucleus

    Syed Afsar Abbas · Anisul Ain Usmani · Usuf Rahaman · Mohammad Ikram

    The issue of whether is doubly magical or not has been a contentious one. Fridmann {\it et al.} (Nature 435 (2005) 922) through studies of two-proton knockout reaction , presented a strong empirical evidence in support of magicity and sphericity of . However in complete conflict with this, Bastin {\it et al.} (Phys. Rev. Lett. 99 (2007) 022503) gave equally strong empirical evidences, to show that the N = 28 magicity had completely collapsed, and that was a well deformed nucleus. At present the popular consensus (Gade {\it et al.}, Phys. Rev. Lett. 122 (2019) 222501) strongly supports the latter one and discards the former one. Here, while we accept the latter experiment as being fine and good, through a careful study of an RMF model calculation, we show that actually the experimental results of Fridmann are also independently good and consistent. As per the Fridmann experiment, the sphericity and magicity of is manifested only through proton number Z=14 being a strong magic number, while the neutron magic number N=28 disappears (or goes into hiding); and still this nucleus is spherical. This is a new and amazing property manifesting itself in this exotic nucleus . In this paper we provide a consistent understanding of this novel reality within a QCD based model. This model, which has been successful in explanation of the halo phenomenon in exotic nuclei, comes forward to provide the physical reason as to why the Fridmann experiment is correct. This QCD based model shows that it is tritons, as elementary entity making up , which then provides consistency to the above amazing conclusions arising from the Fridmann experiment.

    Comments:
    5 pages, 3 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1907.10342 [pdf]
    Indian J.Pure Appl.Phys.(2020)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE