Impact of semi-annihilations on dark matter phenomenology - an example of Z_N symmetric scalar dark matter

TL;DR

This paper investigates how semi-annihilation processes influence dark matter behavior in models with Z_N symmetries, affecting relic abundance and detection prospects, demonstrated through specific scalar dark matter models.

Contribution

It introduces minimal scalar dark matter models with Z_N symmetries that incorporate semi-annihilations, analyzing their impact on dark matter phenomenology.

Findings

Semi-annihilations significantly alter relic abundance.

Dark matter detection prospects are affected by semi-annihilation processes.

Models with Z_3 and Z_4 symmetries show distinct phenomenological features.

Abstract

We study the impact of semi-annihilations x_i x_j <-> x_k X, where x_i is any dark matter and X is any standard model particle, on dark matter phenomenology. We formulate minimal scalar dark matter models with an extra doublet and a complex singlet that predict non-trivial dark matter phenomenology with semi-annihilation processes for different discrete Abelian symmetries Z_N, N>2. We implement two such example models with Z_3 and Z_4 symmetry in micrOMEGAs and work out their phenomenology. We show that both semi-annihilations and annihilations involving only particles from two different dark matter sectors significantly modify the dark matter relic abundance in this type of models. We also study the possibility of dark matter direct detection in XENON100 in those models.