CP violating phases in mu-e conversion

Understand

Experiments are planned to improve the sensitivity of mu-e conversion from the current ~ 10^{-12} to 10^{-16} - 10^{-18}.

• If the muon (bound to the nucleus) could be polarised, a spin asymmetry of the final state electron is sensitive to CP violating phases on lepton flavour violating operators.
• This is similar to extracting phases from asymmetries in the final state spin and phase space distributions of mu to 3e and mu to e gamma.