Probing Hidden Sector Photons through the Higgs Window

TL;DR

This paper explores how a light hidden photon, gaining mass through a hidden Higgs, can be detected via mixing with the standard photon, with implications for experiments and cosmological observations.

Contribution

It introduces the concept of a hidden-Higgs giving mass to hidden photons and analyzes its experimental and cosmological implications, providing new bounds on such particles.

Findings

Stronger bounds on hidden-photon mass in the small mass regime.

Implications for laser polarization and light-shining-through-the-wall experiments.

Constraints from cosmological and astrophysical observations.

Abstract

We investigate the possibility that a (light) hidden sector extra photon receives its mass via spontaneous symmetry breaking of a hidden sector Higgs boson, the so-called hidden-Higgs. The hidden-photon can mix with the ordinary photon via a gauge kinetic mixing term. The hidden-Higgs can couple to the Standard Model Higgs via a renormalizable quartic term - sometimes called the Higgs Portal. We discuss the implications of this light hidden-Higgs in the context of laser polarization and light-shining-through-the-wall experiments as well as cosmological, astrophysical, and non-Newtonian force measurements. For hidden-photons receiving their mass from a hidden-Higgs we find in the small mass regime significantly stronger bounds than the bounds on massive hidden sector photons alone.