Constraining dark photon model with dark matter from CMB spectral distortions

TL;DR

This paper investigates how dark matter interacting via a light mediator can cause spectral distortions in the CMB, and assesses the potential of future experiments like PIXIE to detect such effects, improving constraints on dark sector models.

Contribution

It introduces a method to constrain dark photon models through CMB spectral distortions and compares future experimental sensitivities with existing terrestrial bounds.

Findings

Future PIXIE-like experiments can significantly improve constraints on dark photon models.

CMB spectral distortions provide a complementary probe to terrestrial experiments.

The study quantifies the potential detectability of dark matter interactions via spectral distortions.

Abstract

Many extensions of Standard Model (SM) include a dark sector which can interact with the SM sector via a light mediator. We explore the possibilities to probe such a dark sector by studying the distortion of the CMB spectrum from the blackbody shape due to the elastic scatterings between the dark matter and baryons through a hidden light mediator. We in particular focus on the model where the dark sector gauge boson kinetically mixes with the SM and present the future experimental prospect for a PIXIE-like experiment along with its comparison to the existing bounds from complementary terrestrial experiments.