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Title: The positron excess as a smoking gun for dynamical dark matter?

One of the most puzzling aspects of recent data from the AMS-02 experiment is an apparent rise in the cosmic-ray positron fraction as a function of energy. This feature is observed out to energies of approximately 350 GeV. One explanation of these results interprets the extra positrons as arising from the decays of dark-matter particles. This in turn typically requires that such particles have rather heavy TeV-scale masses and not undergo simple two-body decays to leptons. In this talk, by contrast, we show that Dynamical Dark Matter (DDM) can not only match existing AMS-02 data on the positron excess, but also accomplish this feat with significantly lighter dark-matter constituents undergoing simple two-body decays to leptons. We also demonstrate that the Dynamical Dark Matter framework makes a fairly robust prediction that the positron fraction should level off and then remain roughly constant out to approximately 1 TeV, without experiencing any sharp downturns. Thus, if we interpret the positron excess in terms of decaying dark matter, the existence of a plateau in the positron fraction at energies less than 1 TeV may be taken as a “smoking gun” of Dynamical Dark Matter.
Authors:
 [1] ;  [2] ;  [3]
  1. Department of Physics, University of Arizona, Tucson, AZ 85721 USA and Department of Physics, University of Maryland, College Park, MD 20742 (United States)
  2. Department of Physics, University of Hawaii, Honolulu, HI 96822 (United States)
  3. Department of Physics, Carleton University, Ottawa, Ontario, K1S 5B6 (Canada)
Publication Date:
OSTI Identifier:
22306116
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1604; Journal Issue: 1; Conference: PPC 2013: 7. international conference on interconnections between particle physics and cosmology, Lead-Deadwood, SD (United States), 24 Jun - 6 Jul 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; COSMIC RADIATION; ENERGY DEPENDENCE; FORECASTING; GEV RANGE 100-1000; NONLUMINOUS MATTER; POSITRONS; TEV RANGE 01-10; TWO-BODY PROBLEM