A Robust Search for Lepton Flavour Violating Axions at Mu3e

2023/11/29 by Knapen, Simon, Langhoff, Kevin, Opferkuch, Toby +1 · 2 citations
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2311.17915

Abstract

We propose a search at Mu3e for lepton flavor violating axion(-like) particles in μ→ 3e + a decays. By requiring an additional e⁺e^- pair from internal conversion, one can circumvent the calibration challenges which plague the μ→ e+a channel for axions lighter than 20 MeV. Crucially, the corresponding reduction in signal rate is to a large extent compensated for by Mu3e's ability to resolve highly collimated tracks. For phase I of Mu3e, we project a sensitivity to decay constants as high as 6× 10⁹ GeV which probes uncharted parameter space in scenarios of axion dark matter. The sensitivity to axions which couple primarily to right-handed leptons can be further improved by leveraging the polarisation of the muon beam.

Cited by

• Flavor in Ninths and a Discrete Gauge Origin of the QCD Axion
• Refined Low-Energy Supernova Constraints on Lepton Flavor Violating Axions
• Expanding the Landscape of Exotic Muon Decays

Related

• Displaced Searches for Axion-Like Particles and Heavy Neutral Leptons at Mu3e
• Searching for Lepton Flavour Violation with the Mu3e Experiment
• The Mu3e Experiment
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• The Rare and Forbidden: Testing Physics Beyond the Standard Model with Mu3e