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Title: Phases of cannibal dark matter

A hidden sector with a mass gap undergoes an epoch of cannibalism if number changing interactions are active when the temperature drops below the mass of the lightest hidden particle. During cannibalism, the hidden sector temperature decreases only logarithmically with the scale factor. We consider the possibility that dark matter resides in a hidden sector that underwent cannibalism, and has relic density set by the freeze-out of two-to-two annihilations. We identify three novel phases, depending on the behavior of the hidden sector when dark matter freezes out. During the cannibal phase, dark matter annihilations decouple while the hidden sector is cannibalizing. During the chemical phase, only two-to-two interactions are active and the total number of hidden particles is conserved. During the one way phase, the dark matter annihilation products decay out of equilibrium, suppressing the production of dark matter from inverse annihilations. We map out the distinct phenomenology of each phase, which includes a boosted dark matter annihilation rate, new relativistic degrees of freedom, warm dark matter, and observable distortions to the spectrum of the cosmic microwave background.
 [1] ;  [2] ;  [2] ;  [2]
  1. Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics. New High Energy Theory Center
  2. New York Univ. (NYU), NY (United States). Dept. of Physics. Center for Cosmology and Particle Physics
Publication Date:
Grant/Contract Number:
SC0003883; PHY-1066293
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2016; Journal Issue: 12; Journal ID: ISSN 1029-8479
Springer Berlin
Research Org:
Rutgers Univ., Piscataway, NJ (United States); New York Univ. (NYU), NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF)
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTRONOMY AND ASTROPHYSICS; Beyond Standard Model; Cosmology of Theories beyond the SM
OSTI Identifier: