Superradiant Searches for Dark Photons in Two Stage Atomic Transitions

TL;DR

This paper proposes a novel resonant detection method for dark photon fields using two-photon transitions in cold parahydrogen, significantly improving coupling sensitivity with a modified light-shining-through-wall setup.

Contribution

It introduces a new mechanism leveraging superradiant two-photon transitions in cold gases to detect dark photons with enhanced sensitivity.

Findings

Coupling sensitivity for sub-meV dark photon masses is improved by orders of magnitude.

Numerical simulations demonstrate the nonlinear amplification of dark photon-triggered two-photon emission.

A modified light-shining-through-wall experiment is proposed for practical detection.

Abstract

We study a new mechanism to discover dark photon fields, by resonantly triggering two photon transitions in cold gas preparations. Using coherently prepared cold parahydrogen, coupling sensitivity for sub-meV mass dark photon fields can be advanced by orders of magnitude, with a modified light-shining-through-wall setup. We calculate the effect of a background dark photon field on the dipole moment and corresponding transition rate of cold parahydrogen pumped into its first vibrational excited state by counter-propagating laser beams. The nonlinear amplification of two photon emission triggered by dark photons in a cold parahydrogen sample is numerically simulated to obtain the expected dark photon coupling sensitivity.