High-energy electrons from the muon decay in orbit: radiative corrections

TL;DR

This paper calculates the first-order radiative correction to the high-energy electron spectrum from muon decay in orbit, which is crucial for reducing background in upcoming muon-electron conversion experiments.

Contribution

It provides the first detailed calculation of the O(α) correction to the electron spectrum in muon decay in orbit, aiding experimental background suppression.

Findings

Radiative correction suppresses background by about 15%.

Results are relevant for upcoming Mu2e and COMET experiments.

Enhances precision in muon decay spectrum measurements.

Abstract

We determine the $\mathcal{O}(\alpha)$ correction to the energy spectrum of electrons produced in the decay of muons bound in atoms. We focus on the high-energy end of the spectrum that constitutes a background for the muon-electron conversion and will be precisely measured by the upcoming experiments Mu2e and COMET. The correction suppresses the background by about 15\%.