Hunting dark energy with pressure-dependent photon-photon scattering

TL;DR

This paper proposes a laboratory method to detect dark energy-related chameleon particles by observing pressure-dependent photon-photon scattering, linking environmental mass variation to measurable scattering rates.

Contribution

It introduces a novel experimental approach to directly produce and detect chameleon particles through pressure-dependent photon-photon scattering in a controlled setting.

Findings

Pressure dependence of scattering rate reveals chameleon mass characteristics

Method enables parameter scanning of chameleon models with mass around 0.1-1 μeV

Demonstrates feasibility of laboratory detection of dark energy candidates

Abstract

Toward understanding of dark energy, we propose a novel method to directly produce a chameleon particle and force its decay under controlled gas pressure in a laboratory-based experiment. {\it Chameleon gravity}, characterized by its varying mass depending on its environment, could be a source of dark energy, which is predicted in modified gravity. A remarkable finding is a correspondence between the varying mass and a characteristic pressure dependence of a stimulated photon-photon scattering rate in a dilute gas surrounding a focused photon-beam spot. By observing a steep pressure dependence in the scattering rate, we can directly extract the characteristic feature of the chameleon mechanism. As a benchmark model of modified gravity consistent with the present cosmological observations, a reduced $F(R)$ gravity is introduced in the laboratory scale. We then demonstrate that the proposed method indeed enables a wide-ranging parameter scan of such a chameleon model with the varying mass around $(0.1-1)~[\mu \mathrm{eV}]$ by controlling pressure values.