Constraining vector dark matter and dark photon with degenerate mass in a hidden local SU(2) model

TL;DR

This paper explores a hidden SU(2) gauge sector that produces degenerate vector dark matter and dark photons, analyzing relic density, experimental constraints, and the impact of kinetic mixing on dark matter interactions.

Contribution

It introduces a model with degenerate vector dark matter and dark photon from a hidden SU(2) sector, including kinetic mixing and relic density analysis.

Findings

Dark matter relic density can be achieved within certain mass and coupling ranges.

Direct detection experiments impose the strongest upper limits on dark photon interactions.

Constraints from dark photon physics and dark sector thermalization are significant.

Abstract

We discuss degenerate vector dark matter and dark photon that are induced from hidden $SU(2)_H$ gauge sector where it is spontaneously broken by vacuum expectation value of $SU(2)_H$ doublet. Kinetic mixing between $SU(2)_H$ and $U(1)_Y$ gauge fields can be generated by introducing dimension six operator realizing dark photon interactions. In estimating relic density we focus on the process in which dark matter annihilates into dark photons, and search for the region of dark matter mass and gauge coupling realizing observed relic density. We then discuss constraints from dark photon physics, thermalization of dark sector and direct detection of dark matter. It is then found that constraints from direct detection experiments give us the strongest upper limits on the dark photon interactions.