English  |  正體中文  |  简体中文  |  Items with full text/Total items : 49645/84944 (58%)
Visitors : 7700631      Online Users : 69
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/112533


    Title: The 17 MeV Anomaly in Beryllium Decays and U(1) U ( 1 ) Portal to Dark Matter
    Authors: Chian-Shu Cen;G-L Lin;Y-H Lin;Fanrong Xu
    Date: 2017-11-10
    Issue Date: 2018-01-03 02:10:49 (UTC+8)
    Abstract: The experiment of Krasznahorkay \textit{et al} observed the transition of a 8Be excited state to its ground state and accompanied by an emission of e+e− pair with 17 MeV invariant mass. This 6.8σ anomaly can be fitted by a new light gauge boson. We consider the new particle as a U(1) gauge boson, Z′, which plays as a portal linking dark sector and visible sector. In particular, we study the new U(1) gauge symmetry as a hidden or non-hidden group separately. The generic hidden U(1) model, referred to as dark Z model, is excluded by imposing various experimental constraints. On the other hand, a non-hidden Z′ is allowed due to additional interactions between Z′ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found the search for the DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the DM-electron scattering for MeV-scale DM is still allowed by current constraints for non-hidden U(1) models. It is possible to test the underlying U(1) portal model by the future Si and Ge detectors with 5e− threshold charges.
    Relation: Int. J. Mod. Phys. A 32, 1750178
    DOI: 10.1142/S0217751X17501780
    Appears in Collections:[物理學系暨研究所] 期刊論文

    Files in This Item:

    File SizeFormat
    index.html0KbHTML2View/Open

    All items in 機構典藏 are protected by copyright, with all rights reserved.


    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - Feedback