Annihilating asymmetric dark matter
Abstract
The relic abundance of particle and antiparticle dark matter (DM) need not be vastly different in thermal asymmetric dark matter (ADM) models. By considering the effect of a primordial asymmetry on the thermal Boltzmann evolution of coupled DM and anti-DM, we derive the requisite annihilation cross section. This is used in conjunction with cosmic microwave background and Fermi-LAT gamma-ray data to impose a limit on the number density of anti-DM particles surviving thermal freeze-out. When the extended gamma-ray emission from the Galactic Center is reanalyzed in a thermal ADM framework, we find that annihilation into τ leptons prefer anti-DM number densities 1%-4% that of DM while the b -quark channel prefers 50%-100%.
- Publication:
-
Physical Review D
- Pub Date:
- January 2015
- DOI:
- 10.1103/PhysRevD.91.023505
- arXiv:
- arXiv:1408.5142
- Bibcode:
- 2015PhRvD..91b3505B
- Keywords:
-
- 95.35.+d;
- 12.60.-i;
- Dark matter;
- Models beyond the standard model;
- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 7 pages, 5 figures