Search for in muonic atom at COMET experiment

Search for in muonic atom at COMET experimentMasato Yamanaka (ICRR, Univ. of Tokyo)Collaborators Masafumi Koike (Saitama Univ.)Yoshitaka Kuno (Osaka Univ.)Joe Sato (Saitama Univ. )meeeIntroduction Introduction In Standard Model (SM) Lepton Flavour Violation (LFV) through the neutrino oscillation

But Forever invisibleDiscovery of the LFV signalOne of the evidence for beyond the SMIntroduction Prove for structure of new physicsComparing LFV signals in each process typeDiscrimination of new physics modelsDesire for detectable new LFV process

Supersymetric model Extra dimension model Introduction New idea for LFV searchin muonic atommeeeWhat is sensitive to ?Flavor violation between and emWhere is the stage ?MUSIC, COMET, and PRISMWhat is advantage ?Clean signal, and simultaneous search with other LFV processesmeee meeenucleusmuonelectronMuonic atomelectron 1S orbitmuon 1S orbit meeein muonic atomelectron 1S orbitmuon 1S orbitmeee

LFV vertexInteraction rate meeeelectron 1S orbitmuon 1S orbit

Interaction rateCross section for elemental interactionin muonic atommeeeLFV vertex9 meee

Lagrangian

LFV sourceModel dependent parmeters meee

Lagrangian

meee

Lagrangian

meee

For A g (i = 1, 2, , 6) L(R)=i meeeelectron 1S orbitmuon 1S orbit

Interaction rateOverlap of wave function of and mein muonic atommeeeLFV vertex meeeMuonic atomOverlap of wave functionsMuon localizing at nucleus positon

meee

Branching ratio

Lifetime of free muon (2.197 10 s)-6Lifetime of bound muon 2.19 10 s for H-61(7 - 8) 10 s for U-8238Discovery reachDiscovery reach

Branching ratio ( )megRatio between BR( ) and BR( )meg meeeDiscovery reach

Ratio between BR( ) and BR( )me meeeeeDiscovery reach

Discovery reach

For run-time 1 year 3 10 s710181019-muon at COMET experimentDiscovery reach

can be first signal of LFV !?meeeSummary Summary New LFV processin muonic atommeeeClean signal (back to back electron with E m /2)

Interaction rateAdvantage : Large nucleus =emDetectable in on-going or future experimentsWe wish to observe LFV in the process24Appendix meeenucleusmuonelectronMuonic atomelectron 1S orbitmuon 1S orbitOne of the candidates for beyond the SM Supersymmetric (SUSY) modelSupersymmetry Lepton SleptonGauge boson GauginoSymmetry between boson and fermionStability of Higgs mass, dark matter, gauge coupling unification, hierarchy problem, and so onWhy SUSY models ??