Charged Lepton Flavour Violation

• Beyond-the-Standard Model Physics can cause CLFV

• e.g. massive neutrinos
• but CLFV GIM-suppressed to less than O(10{50)
• essentially background-free for further new physics
• without such cancellations, rates can be much larger
• highly-sensitive probes to BSM physics
• multiple, complementary channels
• e.g. for muons:
• ¹+ → e{ + °
• ¹+ → e{ + e+ + e{
• ¹{ + N → e{ + N (muon-to-electron conversion)