Improved analyses for ${\mu }^{-}{e}^{-}\to e^{-}{e}^{-}$ in muonic atoms by contact interactions

Abstract

The charged lepton flavor violating (CLFV) processes of ${\mu }^{-}{e}^{-}\to e^{-}{e}^{-}$ decay by four Fermi contact interactions in a muonic atom for various atoms are investigated. The wave functions of bound and scattering state leptons are properly treated by solving Dirac equations with Coulomb interaction of the finite nuclear charge distributions. This new effect contributes significantly in particular for heavier atoms, where the obtained decay rate is about one order of magnitude larger than the previous estimation for ${}^{208}$Pb. We find that, as the atomic number $Z$ increases, the ${\mu }^{-}{e}^{-}\to e^{-}{e}^{-}$ decay rates increase more rapidly than the result of the previous work of $Z^3$, suggesting this decay as one of the promising processes to search for CLFV interaction.

10 pages, 7 figures

Cited by in corpus (12)

• New physics at the MUonE experiment at CERN
• Selecting mu -> e Conversion Targets to distinguish Lepton Flavour-Changing Operators
• In-flight cLFV conversion: $e-\mu$, $e-\tau$ and $\mu -\tau$ in minimal extensions of the Standard Model with sterile fermions
• On the role of leptonic CPV phases in cLFV observables
• Search for muon-to-electron conversion with the COMET experiment
• Improved analysis for ${\mu }^{-}{e}^{-}\to e^{-}{e}^{-}$ in muonic atoms by photonic interaction
• A two-loop induced neutrino mass model, dark matter, and LFV processes ${\ell }_i\to {\ell }_j\gamma$, and $\mu e\to ee$ in a hidden local $U(1)$ symmetry
• Measurements of $\mu \to 3e$ Decay with Polarised Muons as a Probe of New Physics
• A radiatively induced neutrino mass model with hidden local $U(1)$ and LFV processes ${\ell }_i\to {\ell }_j\gamma$, $\mu \to e{Z}^{\prime }$ and $\mu e\to ee$
• Model identification in ${\mu }^{-}\to e^{-}$ conversion with invisible boson emission using muonic atoms
• Momentum distribution of the electron pair from the charged lepton flavor violating process ${\mu }^{-}{e}^{-}\to e^{-}{e}^{-}$ in muonic atoms with a polarized muon
• Effective-field theories for charged lepton flavour violation