The Quest for $\mu \to e \gamma$ and its Experimental Limiting Factors at Future High Intensity Muon Beams

TL;DR

This paper analyzes the potential and limitations of future high-intensity muon beams for detecting the rare decay mu to e gamma, focusing on experimental challenges and detector design considerations.

Contribution

It identifies the key experimental limiting factors and evaluates detector designs to optimize sensitivity at extremely high muon beam intensities.

Findings

Limiting factors include background noise and detector resolution.

Sensitivity improves with higher beam intensities up to certain thresholds.

Conceptual detector designs can achieve significant sensitivity gains.

Abstract

The search for the Lepton Flavor Violating decay mu into e gamma will reach an unprecedented level of sensitivity within the next five years thanks to the MEG-II experiment. This experiment will take data at the Paul Scherrer Institut where continuous muon beams are delivered at a rate of about 10^8 muons per second. On the same time scale, accelerator upgrades are expected in various facilities, making it feasible to have continuous beams with an intensity of 10^9 or even 10^10 muons per second. We investigate the experimental limiting factors that will define the ultimate performances, and hence the sensitivity, in the search for mu into e gamma with a continuous beam at these extremely high rates. We then consider some conceptual detector designs and evaluate the corresponding sensitivity as a function of the beam intensity.