Enhancing Dark Matter Annihilation into Neutrinos

TL;DR

This paper analyzes how dark matter can annihilate into neutrinos more efficiently than previously thought, highlighting the importance of neutrino mass mechanisms and providing guidelines for future model development.

Contribution

It offers a quasi model-independent analysis showing conditions for enhanced dark matter annihilation into neutrinos, challenging some existing assumptions in the literature.

Findings

Certain annihilation channels are less suppressed than previously believed.

Neutrino mass generation mechanisms significantly influence annihilation rates.

Numerical examples demonstrate feasible scenarios for enhanced neutrino signals.

Abstract

We perform a detailed and quasi model-independent analysis of direct annihilation of Dark Matter into neutrinos. Considering different cases for scalar and fermionic Dark Matter, we identify several settings in which this annihilation is enhanced, contrary to some statements in the literature. They key point is that several restrictions of, e.g., a supersymmetric framework do not hold in general. The mass generation mechanism of the neutrinos plays an important role, too. We illustrate our considerations by two examples that are not (as usually) suppressed by the smallness of the neutrino mass, for which we also present a numerical analysis. Our results can be easily used as guidelines for model building.