Constraining chameleon field theories using the GammeV afterglow experiments

TL;DR

This paper calculates the afterglow rate for chameleon fields in the GammeV experiment, discusses how constraints depend on assumptions, and forecasts improved bounds from the upcoming GammeV--CHASE experiment on various chameleon models.

Contribution

It provides a detailed calculation of the chameleon afterglow rate and forecasts the enhanced constraints achievable with the next-generation GammeV--CHASE experiment.

Findings

GammeV constrains chameleon couplings to matter and photons.

GammeV--CHASE will significantly improve parameter space coverage.

Constraints can surpass astrophysical and fifth force tests.

Abstract

The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints on various assumptions in the calculation is studied. We discuss GammeV--CHASE, a second-generation GammeV experiment, which will improve upon GammeV in several major ways. Using our calculation of the chameleon afterglow rate, we forecast model-independent constraints achievable by GammeV--CHASE. We then apply these constraints to a variety of chameleon models, including quartic chameleons and chameleon dark energy models. The new experiment will be able to probe a large region of parameter space that is beyond the reach of current tests, such as fifth force searches, constraints on the dimming of distant astrophysical objects, and bounds on the variation of the fine structure constant.