Neutron Interferometry constrains dark energy chameleon fields

TL;DR

This study uses neutron interferometry to measure phase shifts and set limits on chameleon scalar fields, which are candidates for dark energy, thereby constraining their coupling strength.

Contribution

It introduces a novel application of neutron interferometry to constrain dark energy chameleon fields, providing the most stringent limits to date on their coupling constant.

Findings

Coupling constant β < 1.9 × 10^7 at 95% confidence level for n=1

No detectable phase shift attributable to chameleon fields observed

Method improves constraints on dark energy scalar fields

Abstract

We present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant $\beta$ is less than 1.9 $\times10^7$~for $n=1$ at 95\% confidence level, where $n$ is an input parameter of the self--interaction of the chameleon field $\varphi$ inversely proportional to $\varphi^n$.