GammeV: a milli-eV particle search at Fermilab

TL;DR

GammeV is a Fermilab experiment that searches for axion-like and chameleon particles using light-shining-through-a-wall and particle-in-a-jar techniques, setting new limits on their couplings and excluding certain particle interpretations.

Contribution

First to extend limits on photon coupling for axion-like particles in the milli-eV range and to exclude the PVLAS 2006 axion-like particle interpretation.

Findings

Extended limits on axion-like particle couplings

Excluded PVLAS 2006 axion interpretation

Set limits on chameleon particle couplings

Abstract

GammeV is an experiment conducted at Fermilab that employs the light shining through a wall technique to search for axion-like particles and employs a particle in a jar technique to search for dilaton-like chameleon particles. We obtain limits on the coupling of photons to an axion-like particle that extend previous limits for both scalars and pseudoscalars in the milli-eV mass range. We are able to exclude the axion-like particle interpretation of the anomalous PVLAS 2006 result by more than 5 standard deviations. We also present results on a search for chameleons and set limits on their possible coupling to photons.