X-Ray Constraints on Dark Photon Tridents

TL;DR

This paper uses 16 years of INTEGRAL/SPI data to set new constraints on sub-MeV dark photon decay via the trident process, improving limits on kinetic mixing parameters and highlighting future observational prospects.

Contribution

It provides the first comprehensive constraints on dark photon trident decay in the sub-MeV range using X-ray data, and discusses future detection potential.

Findings

Established new bounds on dark photon kinetic mixing between 61 keV and 1022 keV.

Demonstrated the significance of X-ray observations in probing dark photon decay channels.

Highlighted the potential of future X-ray observatories to detect dark photon trident signals.

Abstract

Dark photons that are sufficiently light and/or weakly-interacting represent a compelling vision of dark matter. Dark photon decay into three photons, which we call the dark photon trident, can be the dominant channel when the dark photon mass falls below the electron pair threshold and can produce a significant flux of x-rays. We use 16 years of data from INTEGRAL/SPI to constrain sub-MeV dark photon decay, producing new worlds-best constraints on the kinetic mixing parameter for dark photon masses between 61 keV and 1022 keV, and comment on the potential for future x-ray observatories to discover the trident decay process.