The MEG experiment is currently searching for the lepton-flavor-changing decay μ → eγ. The Standard Model implies the μ → eγ by neutrino oscillations but it cannot be observed in experiments because of too small branching ratio. Many extensions of the Standard Model, however, predict the decay within a reach of the MEG experiment and it is a clear evidence of new physics. A liquid xenon gamma-ray detector and a positron spectrometer with a gradient magnetic field enables better sensitivity than the current limit by two orders of magnitude. The physics data taking started in 2008 and then upgrades of the detector brought a stable operation in 2009-year run. We report the preliminary result on the 2009 data together with a current status and a future of the experiment. The obtained upper limit of the branching ratio is Br(μ+ → e+γ) < 1.5 × 10 -11 at 90% confidence level (C.L.).
|ジャーナル||Journal of Physics: Conference Series|
|出版ステータス||Published - 2012|
|イベント||2nd International Conference on Particle Physics in Memoriam Engin Arik and Her Colleagues, ICPP-Istanbul II - Istanbul, Turkey|
継続期間: 2011 6 20 → 2011 6 25
ASJC Scopus subject areas