COMET

μ-e conversion search from muonic aluminium J-PARC pulsed proton beam to produce pulsed muon beam Forbidden in the Standard Model  clue to the new physics beyond the Standard Model μ  eγ vs. μ-e conversion μ  e γ ~100 times larger when the photonic process dominates μ-e conversion Sensitive also to the non- photonic contribution proton pulse prompt background muon decay

COMET Phase I < COMET Phase II < % C.L. Upper Limit

COMET μ-e conversion search with a sensitivity of Phase I Phase II Phase I – Beam background study and achieving an intermediate sensitivity of < GeV, ~3.2kW, ~3 weeks of DAQ Physics DAQ in Phase II – 8GeV, ~56 kW, 1 year DAQ to achieve the COMET final goal of < sensitivity Starts around MeV/c Phase I 0.03 BG expected in 1.5x10 6 sec running time 4 Proton beam Pion production target Radiation shield Capture solenoid ~5T Transport solenoid Beam collimator COMET Phase-I Detector Detector solenoid muons

COMET Phase I Facility Schedule 2013 – Design of the building & beam line Bid tendering and start construction – Design of superconducting solenoid magnets and start of construction Production of SC wires as well – Design of the pion production target 2014 – Completion of the building – Construction of superconducting solenoid magnets – Start magnet and radiation shielding (and beam dump) installation Transport solenoid – Start preparation of cryogenic system – Tests of the target production target 2015 – Construction of superconducting solenoid magnets – Preparation of cryogenic system – Construction of the pion production target 2016 – Installation of the capture solenoid – Completion of the cryogenic system Tests of the magnet system – Installation of the target – Ready to accept the 8GeV beam JFY COMET building design construction Solenoid magnet SC wire Capture magnet Transport magnet Cryogenic system Magnet system test Radiation shield Beam dump Pion target Design & test construction

COMET & Mu2e schedule

COMET Collaboration Proposal 2007 – 18 members from 3 countries CDR 2009 – 48 members from 4 countries Phase I LoI 2012 – 106 members from 11 countries Phase I Proposal 2013 – 110 members from 11 countris Phase I TDR 2013 – 131 members from 12 countries

Collaborative works between Mu2e & COMET Superconducting magnet R&D – KEK expertise of aluminum-stabilized SC cable – FNAL test facility Measurement of proton emission (~ 200MeV/c) after muon capture – Largest contribution to the detector hit rate – No cross-section data of aluminum