Electro-Weak Dark Matter: non-perturbative effect confronting indirect detections

TL;DR

This paper updates constraints on Electroweak Dark Matter considering non-perturbative effects, showing that many models are ruled out up to 20 TeV, but some regions remain viable and future experiments will probe remaining parameter space.

Contribution

It incorporates the Sommerfeld-Ramsauer-Townsend effect into indirect detection constraints, providing updated limits on various EWDM models and identifying conditions under which they evade current bounds.

Findings

Hypercharged triplet and higher multiplet EWDMs are ruled out up to 10-20 TeV.

Majorana triplet EWDM can evade constraints near Ramsauer-Townsend dips.

Future CTA observations will test most remaining parameter space.

Abstract

We update indirect constraints on Electro-Weak Dark Matter (EWDM) considering the Sommerfeld-Ramsauer-Townsend (SRT) effect for its annihilations into a pair of standard model gauge bosons assuming that EWDM accounts for the observed dark matter (DM) relic density for a given DM mass and mass gaps among the multiplet components. For the radiative or smaller mass splitting, the hypercharged triplet and higher multiplet EWDMs are ruled out up to the DM mass ~ 10 - 20 TeV by the combination of the most recent data from AMS-02 (antiproton), Fermi-LAT (gamma-ray), and HESS (gamma-line). The Majorana triplet (wino-like) EWDM can evade all the indirect constraints only around Ramsauer-Townsend dips which can occur for a tiny mass splitting of order 10 MeV or less. In the case of the doublet (Higgsino-like) EWDM, a wide range of its mass > 500 GeV is allowed except Sommerfeld peak regions. Such a stringent limit on the triplet DM can be evaded by employing a larger mass gap of the order of 10 GeV which allows its mass larger than about 1 TeV. However, the future CTA experiment will be able to cover most of the unconstrained parameter space.