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arXiv · 0906.3009

Generic dark matter signature for gamma-ray telescopes

V. Barger·Y. Gao·W. -Y. Keung·D. Marfatia
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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^-γhas 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).

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V. Barger, Y. Gao, W. -Y. Keung, D. Marfatia. 2009-09-14. Generic dark matter signature for gamma-ray telescopes. https://doi.org/10.1103/physrevd.80.063537

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