Constraining dark photon parameters based on the very high energy observations of blazars

TL;DR

This paper uses very high energy observations of blazars to set new constraints on dark photon parameters, specifically the kinetic mixing, by analyzing photon interactions in dense dark matter regions around black holes.

Contribution

It introduces a novel method to constrain dark photon kinetic mixing using VHE photon absorption in dense dark matter environments near blazars.

Findings

Kinetic mixing constrained to ~10^{-7} at 95% confidence level

Constraints applicable for dark photon masses between 0.03 and 1 eV

Analysis based on observations of Mrk 421 and Mrk 501

Abstract

Dark photon is a new gauge boson beyond the Standard Model as a kind of dark matter (DM) candidate. Dark photon dark matter (DPDM) interacts with electromagnetic fields via kinetic mixing, implicating an approach to give a constraint with extragalactic very high energy (VHE) sources. In this work, we attempt to constrain the kinetic mixing from the photon-dark photon scattering process in the host galaxy of blazar, the intergalactic medium and the Milky Way. The VHE photons from a blazar would pass through a dense DM spike around the supermassive black hole where the absorption from DPDM is dramatically enhanced. The kinetic mixing is constrained to be $\epsilon \sim 10^{-7}$ at a 95$\%$ confidence level with $m_{\rm D}\sim 0.03 - 1$ eV mass range from the observations of Markarian (Mrk) 421 and Mrk 501.