Nonthermal production of WIMPs, cosmic e{sup {+-}} excesses, and {gamma} rays from the Galactic Center
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
- Department of Physics, McGill University, Montreal, QC, H3A 2T8 (Canada)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States)
- Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
- Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 10049 (China)
In this paper we propose a dark matter model and study aspects of its phenomenology. Our model is based on a new dark matter sector with a U(1)' gauge symmetry plus a discrete symmetry added to the standard model of particle physics. The new fields of the dark matter sector have no hadronic charges and couple only to leptons. Our model cannot only give rise to the observed neutrino mass hierarchy, but can also generate the baryon number asymmetry via nonthermal leptogenesis. The breaking of the new U(1)' symmetry produces cosmic strings. The dark matter particles are produced nonthermally from cosmic string loop decay which allows one to obtain sufficiently large annihilation cross sections to explain the observed cosmic ray positron and electron fluxes recently measured by the PAMELA, ATIC, PPB-BETS, Fermi-LAT, and HESS experiments while maintaining the required overall dark matter energy density. The high velocity of the dark matter particles from cosmic string loop decay leads to a low phase space density and thus to a dark matter profile with a constant density core in contrast to what happens in a scenario with thermally produced cold dark matter where the density keeps rising towards the center. As a result, the flux of {gamma} rays radiated from the final leptonic states of dark matter annihilation from the Galactic center is suppressed and satisfies the constraints from the HESS {gamma}-ray observations.
- OSTI ID:
- 21308597
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 80, Issue 10; Other Information: DOI: 10.1103/PhysRevD.80.103502; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANNIHILATION
ASYMMETRY
BARYON NUMBER
COSMIC RADIATION
CROSS SECTIONS
DENSITY
ELECTRONS
ENERGY DENSITY
GAMMA RADIATION
GAUGE INVARIANCE
HADRONS
MASS
NEUTRINOS
NONLUMINOUS MATTER
PARTICLE DECAY
PARTICLE PRODUCTION
PHASE SPACE
POSITRONS
SIMULATION
STANDARD MODEL
SYMMETRY
U-1 GROUPS
VELOCITY