Toshiyuki Iwamoto - Lepton flavor violating muon decay search: MEG results and MEG II status
RTG seminar on February 12th, 2020
The MEG experiment, which is to search for charged lepton flavor violating muon decay μ+ → e+γ, had been successfully finished in 2013. The final sensitivity was 5.3 × 10-13, and since the experiment did not find any signal, the upper limit of the branching ratio of the μ+ → e+γ was set to be 4.2 × 10-13 at 90% CL. This result is most stringent to date, and provides important constraints on the existence of the new physics beyond the standard model. The MEG II experiment will improve the sensitivity by an order of magnitude with the new detector technologies. The target sensitivity is 6 × 10-14 with three years data taking. The full engineering run followed by the physics run will be started this year with all the detectors and the electronics. In this talk, after the general introduction of the charged lepton flavor violation, the results of the MEG experiment are discussed, and then the current status and the prospects of the MEG II experiment will be mainly discussed.