Flavor-changing Lorentz and CPT violation in muonic atoms

TL;DR

This paper investigates flavor-changing Lorentz and CPT violation effects in muonic atoms, deriving constraints from existing experiments and estimating future sensitivities for upcoming experiments, thus advancing tests of fundamental symmetries.

Contribution

It provides the first constraints on flavor-changing Lorentz and CPT violation in muonic atoms using effective field theory and experimental data, and estimates sensitivities for future experiments.

Findings

Constraints on Lorentz violation coefficients at parts in 10^{-12} GeV^{-1} and 10^{-13} GeV^{-2}.

Existing data limits flavor-changing electromagnetic muon decays.

Future experiments could improve sensitivity to these violations.

Abstract

Flavor-changing signatures of Lorentz and CPT violation involving muon-electron conversions in muonic atoms are studied using effective field theory. Constraints on coefficients for Lorentz violation at parts in $10^{-12}$ GeV$^{-1}$ for flavor-changing electromagnetic muon decays and parts in $10^{-13}$ GeV$^{-2}$ for flavor-changing 4-point quark-lepton interactions are extracted using existing data from the SINDRUM II experiment at the Paul Scherrer Institute. Estimates are provided for sensitivities attainable in the forthcoming experiments Mu2e at Fermilab and COMET at the Japan Proton Accelerator Complex.