PaperPanorama

Nuclear Theory·nucl-th

Wednesday·January 17, 2018

5 papers3 primary·2 cross-listed

  1. 04

    [Submitted on 21 Sept 2017] (cross-list from nucl-ex)

    Reorientation-effect measurement of the first 2 state in C: confirmation of oblate deformation

    M. Kumar Raju · J. N. Orce · P. Navratil · G. C. Ball · T. E. Drake · S. Triambak · G. Hackman · C. J. Pearson · the TIGRESS/UWC Collaboration

    A Coulomb-excitation reorientation-effect measurement using the TIGRESS ray spectrometer at the TRIUMF/ISAC II facility has permitted the first determination of the diagonal matrix element in C from particle coincidence data. Required state-of-the-art no-core shell model calculations of the nuclear polarizability for the ground and first-excited (2) states in C using chiral NN NLO500 and NN+3NF350 interactions have been performed. Consistent predictions show a larger polarizability than previously anticipated. The polarizability of the 2 state is introduced into the current and previous Coulomb-excitation reorientation-effect analysis of C. Spectroscopic quadrupole moments of eb and eb are determined, respectively, yielding a weighted average of eb, in agreement with recent ab initio calculations. The present measurement confirms that the 2 state of C is oblate and emphasizes the important role played by the nuclear polarizability in Coulomb-excitation studies of light nuclei.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1709.07501 [pdf]
    PLB(2018)·25 citations
  2. 05

    [Submitted on 3 Jan 2018] (cross-list from hep-ph)

    Dark Matter Interpretation of the Neutron Decay Anomaly

    Bartosz Fornal🇺🇸 · Benjamin Grinstein🇺🇸

    There is a long-standing discrepancy between the neutron lifetime measured in beam and bottle experiments. We propose to explain this anomaly by a dark decay channel for the neutron, involving one or more dark sector particles in the final state. If any of these particles are stable, they can be the dark matter. We construct representative particle physics models consistent with all experimental constraints.

    Comments:
    5 pages, 2 figures; v2: references added, further nuclear physics experimental signatures proposed; v3: published PRL version with an extended section on and some inline equations highlighted for visibility
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1801.01124 [pdf]
    PRL(2018)·262 citations

Affiliations

first authorsco-authorsvia INSPIRE