New and accelerator research facility, using MW-class high power proton beams at both 3 GeV and 30 GeV. J-PARC Tokai KEK Tsukuba

LINAC 400 MeV Rapid Cycle Synchrotron Energy : 3 GeV Repetition : 25 Hz Design Power : 1 MW Main Ring Max Energy : 30 GeV Design Power for FX : 0.75 MW Expected Power for SX : > 0.1 MW

LINAC 400 MeV Rapid Cycle Synchrotron Material and Life Science Facility Energy : 3 GeV Repetition : 25 Hz Design Power : 1 MW Main Ring Max Energy : 30 GeV Design Power for FX : 0.75 MW Expected Power for SX : > 0.1 MW

LINAC 400 MeV Neutrino beam to Kamioka Rapid Cycle Synchrotron Material and Life Science Facility Energy : 3 GeV Repetition : 25 Hz Design Power : 1 MW Main Ring Max Energy : 30 GeV Design Power for FX : 0.75 MW Expected Power for SX : > 0.1 MW

LINAC 400 MeV Neutrino beam to Kamioka Rapid Cycle Synchrotron Material and Life Science Facility Nuclear and Particle Physics Exp. Hall Energy : 3 GeV Repetition : 25 Hz Design Power : 1 MW Main Ring Max Energy : 30 GeV Design Power for FX : 0.75 MW Expected Power for SX : > 0.1 MW

" # $ $ % & ' ' ( ) * * +, + + ' ( ) * +, = c E B c E a B a m e β η β γ ω µ µ 2 1 1 2 g=2(1+a μ )

" # $ $ % & ' ' ( ) * * +, + + ' ( ) * +, = c E B c E a B a m e β η β γ ω µ µ 2 1 1 2 g=2(1+a μ )

D.#Nomura#(tau2012)

ω a ω p

muon g-2/edm measurements Anomalous magnetic moment (g-2) a μ = (g-2)/2 = 11 659 208.9 (6.3) x 10-10 (BNL E821 exp) 0.5 ppm 11 659 182.8 (4.9) x 10-10 (standard model) Δa μ = Exp - SM = 26.1 (8.0) x 10-10 3σ anomaly

muon g-2/edm measurements " # $ $ % & ' ' ( ) * * +, + + ' ( ) * +, = c E B c E a B a m e β η β γ ω µ µ 2 1 1 2 In uniform magnetic field, muon spin rotates ahead of momentum due to g-2 = 0 general form of spin precession vector: Anomalous magnetic moment (g-2) a μ = (g-2)/2 = 11 659 208.9 (6.3) x 10-10 (BNL E821 exp) 0.5 ppm 11 659 182.8 (4.9) x 10-10 (standard model) Δa μ = Exp - SM = 26.1 (8.0) x 10-10 3σ anomaly

muon g-2/edm measurements " # $ $ % & ' ' ( ) * * +, + + ' ( ) * +, = c E B c E a B a m e β η β γ ω µ µ 2 1 1 2 In uniform magnetic field, muon spin rotates ahead of momentum due to g-2 = 0 ω = e m a µ B+ η 2 β B+ E c & ' ( ) * +, -. / 0 1 BNL E821 approach γ=30 (P=3 GeV/c) general form of spin precession vector: Continuation at FNAL with 0.1ppm precision Anomalous magnetic moment (g-2) a μ = (g-2)/2 = 11 659 208.9 (6.3) x 10-10 (BNL E821 exp) 0.5 ppm 11 659 182.8 (4.9) x 10-10 (standard model) Δa μ = Exp - SM = 26.1 (8.0) x 10-10 3σ anomaly

muon g-2/edm measurements Anomalous magnetic moment (g-2) a μ = (g-2)/2 = 11 659 208.9 (6.3) x 10-10 (BNL E821 exp) 0.5 ppm 11 659 182.8 (4.9) x 10-10 (standard model) Δa μ = Exp - SM = 26.1 (8.0) x 10-10 3σ anomaly In uniform magnetic field, muon spin rotates ahead of momentum due to g-2 = 0 general form of spin precession vector: e &, ω = $ aµ B * aµ m $ % + ω = e, m a. µ B+ η - 2 BNL E821 approach γ=30 (P=3 GeV/c) γ 2 & ( β B+ ' 1 1 E c ) ' ( )/ + 1 * 0 Continuation at FNAL with 0.1ppm precision β E c + η, * β B 2 + + E c )# ' (" & = e η $ a B + B m % 2 ω µ J-PARC approach E = 0 at any γ ( )# β " Proposed at J-PARC with 0.1ppm precision

Expected time spectrum of µàe + νν decay Muon spin precesses with time. à number of high energy e + changes with time by the frequency : p>200 MeV/c & = e η $ a B + B m % 2 ω µ ( )# β " ω e + decay time (sec)

Expected time spectrum of µàe + νν decay EDM tilts the precession axis. à This yields an up-down decay asymmetry in number of e+ (oscillates with the same frequency ω) & = e η $ a B + B m % 2 ω µ ( )# β " Up-down asymmetry p>200 MeV/c ω d µ =2E-20 ecm EDM e+ decay time (sec)

New Muon g-2/edm Experiment at J-PARC with Ultra-Cold Muon Beam 3 GeV proton beam ( 333 ua) Graphite target (20 mm) Surface muon Surface muon beam (28 MeV/c, 4x10 8 /s) Muonium Production (300 K ~ 25 mev2.3 kev/c) 66 cm Silicon Tracker Super Precision Storage Magnet (3T, ~1ppm local precision) Ultra Cold µ+ Source Resonant Laser Ionization of Muonium (10 6 µ + /s) Muon LINAC (300 MeV/c) Muon storage 1. Ultra-cold μ + beam is injected to storage magnet. 2. Pulse kicker stops muons in storage area 3. Positron tracker measures e+ from μ + àe + νν decay for the period of 33μs5 x lifetime

Muon storage magnet and detector Iron yoke Cryogenics Muon storage orbit e+ tracking detector Super conducting coils 2900 mm Radial tracking vanes (Silicon strip) Positron track 666 mm μ decay vertex p(e+) > 200 MeV/c 13

Silica aerogel with holes (laser ablation) Flat aerogel Data(Mu+BG) BG drilled aerogel 4mm Preliminary Prepared by M. Tabata (Chiba) and Y. Oishi (RIKEN)

High power Ly-α laser Center Wavelength: 122.09 nm (= Mu Lyman-α Line) Output Energy : 100 µj Pulsewidth τ : 2 ns Bandwidth Δν : 230 GHz (for hot W) Repetition Rate : 25 Hz Being developed by RIKEN group Two-Photon Resonance Four-wave mixing in Kr gas New system installed at MLF U-line ω Ly-α = 2ω 1 - ω 2 Kr 4p 5 5p ω 1 : 212.556 nm ω 1 : 212.556 nm ω 2 : 820.649 nm ω Ly-α : 122.089 nm Lyman α Kr 4p 6

Implication to statistical sensitivity With drilled aerogel target, one expects Ultra-cold muon rate : 0.2E+6/sec (*) Running time : 1E+7 sec (120 day) polarization 100 % 50% Statistical uncertainty on ω a : 0.22ppm (0.44ppm) Statistical uncertainty on d μ : 4.4E-21 ecm (8.8E-21 ecm) Good enough to test BNL E821 g-2 results * factor of two more muons with SiC target is not included.

µ µ à e ν ν µ + ( A, Z) à ν µ + (A,Z 1) µ +(A, Z) à e +(A,Z)

µ µ à e ν ν µ + ( A, Z) à ν µ + (A,Z 1) µ +(A, Z) à e +(A,Z)

SINDRUM II µ Rext= number of proton between pulses number of proton in a pulse

capture in the moderator (see also Fig.3.1 and the discussion in the text). e m t 10 3 run2000 on gold SINDRUM II measurement µe2ν simulation µe simulation at B=10-11 a i a events / 100 kev 10 2 10 t F f o 1 T 70 80 90 100 ETOT (MeV) N w

DeeMe

Acceptance (sr/mev/c) 0.25 From a Target 40 H-port Frange GV Entrance GV Exit HS2 Entrance HS3 Entrance HSEP Entrance 0.2 HB4 Entrance HB4 Exit HQ2 Entrance Focus 0.15 0.1 0.05 0 70 80 90 100 110 120 130 Momentum (MeV/c)

Proton beam Pion production target Radiation shield Muon beam transport solenoid Matching solenoid Capture solenoid COMET Solenoids and Detectors for the CDR version 090609.001 Late-arriving particle tagger Beam collimator Muon stopping target Muon target solenoid Beam blocker DIO blocker Calorimeter Tracker Detector solenoid Curved sepctrometer solenoid Figure 5.14: Present design of the solenoid channel used in the tracking studies. 5.3.2.2 Dipole fields for drift compensation To keep the center of the helical trajectories of the muons with reference momentum p 0 in the bending plane, a compensating vertical dipole field should be applied. The magnitude of the compensating dipole field is given by B comp = 1 ( p 0 cos θ 0 + 1 ), (5.6) qr 2 cos θ 0

Switch Yard Beamline Elements A-Line B-Line Beam line component installation in progress in SY since 2014 Beam transport line in HD hall SC magnets Hall construction He compressor used for E36 will be reused for COMET Significant construction work 2016 Summer to connect SY and Hall along the B-Line 90 deg. Transport Solenoid installed in Spring 2015 COMET Hall ready in Spring 2015

All geometry implemented in the full simulation: ICEDUST Detector for physics measurement in Phase I CDC : the main detector of COMET Phase-I Physics Beam test @ PSI 2015 Trigger Hodoscope Counter Scintillator + Cerenkov Analysis algorithm development in progress using simulation data. ex) track finding in CyDET Total ~20,000 wire stringing completed in Nov. 2015 at KEK CDC Read Out Electronics RECBE production at IHEP

Straw tracker (operational in vacuum) prototype Detector for beam BG measurement in Phase I and physics measurement in Phase II ECal (LYSO) R&D using prototypes 100 MeV electron Ecal Pile-up study using simulation data Crystal quality test bench at JINR Wave form taken in the test ß Electron beam test at ELPH Ecal PID performance evaluation at PSI 2015