Vector SIMP dark matter

TL;DR

This paper explores vector SIMP dark matter from an $SU(2)_X$ gauge theory, demonstrating mechanisms for thermal equilibrium with the visible sector via dark Higgs and vector portals, consistent with experimental limits.

Contribution

It provides an explicit model of vector SIMP dark matter with novel portal interactions ensuring thermal contact with the Standard Model.

Findings

Dark Higgs portal can maintain thermal equilibrium.

Massive dark vector portal with Chern-Simons couplings is viable.

Model remains consistent with experimental constraints.

Abstract

Strongly Interacting Massive Particles (SIMPs) have recently been proposed as light thermal dark matter relics. Here we consider an explicit realization of the SIMP mechanism in the form of vector SIMPs arising from an $SU(2)_X$ hidden gauge theory, where the accidental custodial symmetry protects the stability of the dark matter. We propose several ways of equilibrating the dark and visible sectors in this setup. In particular, we show that a light dark Higgs portal can maintain thermal equilibrium between the two sectors, as can a massive dark vector portal with its generalized Chern-Simons couplings to the vector SIMPs, all while remaining consistent with experimental constraints.