The Advanced Muon Facility: a proposed multi-purpose muon facility at Fermilab

TL;DR

The paper proposes the Advanced Muon Facility at Fermilab, a multi-purpose muon storage ring designed to significantly advance charged lepton flavor violation experiments and explore new physics beyond current capabilities.

Contribution

It introduces the concept and initial design considerations for the AMF, aiming to enable ultra-sensitive CLFV experiments and potential follow-up measurements in case of signals.

Findings

Conceptual framework for AMF development

Potential for orders-of-magnitude sensitivity improvements

Synergies with proposed muon collider

Abstract

Charged lepton flavor violation (CLFV) is expected in a diverse set of new physics scenarios. The current generation of experiments probe CLFV in the muon sector in three complementary channels: $\mu^-N \rightarrow e^- N$ (Mu2e, COMET), $\mu^+ \rightarrow e^+ \gamma$ (MEG-II), and $\mu^+ \rightarrow e^+e^+e^-$s (Mu3e). These experiments aim to enhance existing limits by several orders-of-magnitude in the coming decade and offer discovery potential to many new physics models. The proposed Advanced Muon Facility (AMF) would be a multi-purpose muon facility based at Fermilab and introduces an innovative approach based on a muon storage ring to enable a full suite of muon CLFV experiments. AMF would host CLFV experiments with sensitivities orders-of-magnitude beyond the present era. In the event of a signal in these currently planned experiments, AMF would enable additional measurements to elucidate the nature of the new physics observed. The design and R$\&$D for AMF is in its infancy. This article outlines the motivations for AMF, detailing on-going R$\&$D efforts, and highlighting potential synergies with the proposed muon collider.