Generic dark matter signature for gamma-ray telescopes
Abstract
We describe a characteristic signature of dark matter (DM) annihilation or decay into gamma-rays. We show that if the total angular momentum of the initial DM particle(s) vanishes, and helicity suppression operates to prevent annihilation/decay into light fermion pairs, then the amplitude for the dominant 3-body final state f^+f^-\gamma has a unique form dictated by gauge invariance. This amplitude and the corresponding energy spectra hold for annihilation of DM Majorana fermions or self-conjugate scalars, and for decay of DM scalars, thus encompassing a variety of possibilities. Within this scenario, we analyze Fermi LAT, PAMELA and HESS data, and predict a hint in future Fermi gamma-ray data that portends a striking signal at atmospheric Cherenkov telescopes (ACTs).
Keywords
Cite
@article{arxiv.0906.3009,
title = {Generic dark matter signature for gamma-ray telescopes},
author = {V. Barger and Y. Gao and W. -Y. Keung and D. Marfatia},
journal= {arXiv preprint arXiv:0906.3009},
year = {2009}
}
Comments
9 pages, 4 figures. Version to appear in PRD