Neutrinophilic Super-Resonant Dark Matter

TL;DR

This paper explores super-resonant dark matter annihilation into neutrinos, analyzing how kinetic decoupling affects relic density and constraining models with current and future experimental data.

Contribution

It introduces a detailed analysis of super-resonant dark matter annihilation into neutrinos, emphasizing the role of kinetic decoupling and providing new constraints on model parameters.

Findings

Kinetic decoupling significantly impacts relic density calculations.

Current data constrains super-resonant dark matter models with neutrino final states.

Future experiments could further test these models.

Abstract

Dark matter (DM) annihilation can be significantly enhanced through narrow resonances or the Sommerfeld enhancement effect, with both mechanisms potentially combining in a super-resonant annihilation process. In such scenarios, the conventional assumption that kinetic equilibrium persists until chemical decoupling may not hold, leading to substantial impacts on the final DM relic density. However, a strongly enhanced annihilation cross section into Standard Model particles, except neutrinos, is constrained by cosmic microwave background observations. We thus investigate DM annihilation into neutrino pair final states, focusing on the role of kinetic decoupling. We solve the coupled Boltzmann equations to determine the relic density and constrain the parameter space using current experimental data, while also forecasting the sensitivity of future experiments.