Mu2e-II: Muon to electron conversion with PIP-II

TL;DR

Mu2e-II aims to significantly enhance the sensitivity of muon to electron conversion experiments, providing a crucial test for physics beyond the Standard Model and building on the Mu2e experiment's foundation.

Contribution

This paper proposes an upgrade to the Mu2e experiment, called Mu2e-II, which aims to improve sensitivity by at least an order of magnitude, advancing the search for Charged Lepton Flavor Violation.

Findings

Mu2e-II could achieve at least ten times greater sensitivity.

The upgrade leverages PIP-II for high-intensity muon beams.

It represents a logical next step in high-intensity muon research.

Abstract

An observation of Charged Lepton Flavor Violation (CLFV) would be unambiguous evidence for physics beyond the Standard Model. The Mu2e and COMET experiments, under construction, are designed to push the sensitivity to CLFV in the mu to e conversion process to unprecedented levels. Whether conversion is observed or not, there is a strong case to be made for further improving sensitivity, or for examining the process on additional target materials. Mu2e-II is a proposed upgrade to Mu2e, with at least an additional order of magnitude in sensitivity to the conversion rate over Mu2e. The approach and challenges for this proposal are summarized. Mu2e-II may be regarded as the next logical step in a continued high-intensity muon program at FNAL.