Spectroscopy with cold and ultra-cold neutrons

TL;DR

This paper introduces two innovative spectroscopy techniques for cold and ultra-cold neutrons, enabling precise studies of neutron decay and testing gravity laws at short distances, with implications for dark energy research.

Contribution

The paper presents two novel spectroscopy methods: one using the b drift effect for neutron beta-decay studies and another called gravity resonance spectroscopy for testing Newtonian gravity.

Findings

Achieved 10^{-4} level precision in neutron beta-decay measurements.

Set new constraints on short-range gravity interactions.

Significantly improved limits on dark energy chameleon fields.

Abstract

We present two new types of spectroscopy methods for cold and ultra-cold neutrons. The first method, which uses the \RB drift effect to disperse charged particles in a uniformly curved magnetic field, allows to study neutron $\beta$-decay. We aim for a precision on the 10$^{-4}$ level. The second method that we refer to as gravity resonance spectroscopy (GRS) allows to test Newton's gravity law at short distances. At the level of precision we are able to provide constraints on any possible gravity-like interaction. In particular, limits on dark energy chameleon fields are improved by several orders of magnitude.