http://arxiv.org/abs/2002.04038
We present a new mechanism for thermally produced dark matter, based on a semi-annihilation-like process, $\chi+ \chi +\text{SM} \rightarrow \chi + \text{SM}$, with intriguing consequences for the properties of dark matter. First, its mass is low, $\lesssim 1$ GeV (but $\gtrsim 5$ keV to avoid structure-formation constraints). Second, it is strongly interacting, leading to kinetic equilibrium between the dark and visible sectors, avoiding the structure-formation problems of $\chi+ \chi + \chi \rightarrow \chi + \chi$ models. Third, in the $3 \rightarrow 2$ process, one dark matter particle is consumed, giving the standard-model particle a monoenergetic recoil. We show that this new scenario is presently allowed, which is surprising (perhaps a “minor miracle”). However, it can be systematically tested by novel analyses in present and near-term experiments.
J. Smirnov and J. Beacom
Wed, 12 Feb 20
28/58
Comments: 5 pages plus Supplemental Material, comments are welcome