Model identification in $\mu^-\to e^-$ conversion with invisible boson emission using muonic atoms

TL;DR

This paper explores how muonic atom experiments can help identify properties of light neutral bosons emitted during muon-to-electron conversion, emphasizing the spectrum's model dependence near the endpoint.

Contribution

It introduces a method to analyze the electron spectrum in muonic atoms for distinguishing different models of light boson emission.

Findings

Spectrum near high-energy endpoint is highly model-dependent.

Future muonic atom experiments can effectively identify exotic boson properties.

The study provides calculations for various emission scenarios.

Abstract

In this article, we investigate the $\mu^-\to e^-X$ process in a muonic atom, where $X$ is a light neutral boson. By calculating the spectrum of the emitted electron for several cases, we discuss the model-discriminating power of the process. We report the strong model dependence of the spectrum near a high-energy endpoint. Our findings show that future experiments using muonic atoms are helpful to identify the properties of exotic bosons.