Constraining Photon Portal Dark Matter with Texono and Coherent Data

TL;DR

This paper investigates how dark matter interacting via a photon portal affects electron and nuclear recoil events, using TEXONO and COHERENT data to constrain dark matter models, especially for masses below 30 MeV.

Contribution

It provides new constraints on photon portal dark matter models using recent experimental data, especially highlighting the role of COHERENT in the low-mass regime.

Findings

COHERENT data rules out certain thermal relic parameter regions.

COHERENT sets leading constraints for DM masses below 30 MeV.

Dark photon interactions can significantly impact direct detection signals.

Abstract

Dark matter may reside in sector without Standard Model (SM) gauge interactions. One way in which such a dark sector can still impact SM particles through non-gravitational interactions is via the "photon portal" in which a dark photon kinetically mixes with the ordinary SM photon. We study the implications of this setup for electron recoil events at TEXONO reactor and nuclear recoil events at the COHERENT experiment. We find that the recent COHERENT data rules out previously allowed regions of parameter space favored by the thermal relic hypothesis for the DM abundance. When mapped onto the DM-electron cross section, we find that COHERENT provides the leading direct constraints for DM masses < 30 MeV.