Millicharged Relics Reveal Massless Dark Photons
Abstract
The detection of massless kinetically-mixed dark photons is notoriously difficult, as the effect of this mixing can be removed by a field redefinition in vacuum. In this work, we study the prospect of detecting massless dark photons in the presence of a cosmic relic directly charged under this dark electromagnetism. Such millicharged particles, in the form of dark matter or dark radiation, generate an effective dark photon mass that drives photon-to-dark photon oscillations in the early universe. We also study the prospect for such models to alleviate existing cosmological constraints on massive dark photons, enlarging the motivation for direct tests of this parameter space using precision terrestrial probes.
Keywords
Cite
@article{arxiv.2211.05139,
title = {Millicharged Relics Reveal Massless Dark Photons},
author = {Asher Berlin and Jeff A. Dror and Xucheng Gan and Joshua T. Ruderman},
journal= {arXiv preprint arXiv:2211.05139},
year = {2023}
}
Comments
16 pages, 3 appendices, 6 figures; v2, minor improvements to the text, references added, results and conclusions unchanged