1. The TREK program at J-PARC * Hampton University & Jefferson Lab, Virginia, USA APS April Meeting 2011, April 30 – May 2, 2011, Anaheim, California Michael Kohl * Supported by DOE Early Career Award DE-SC0003884 and partially by NSF grant PHY-0855473

2. 2 East Japan Great Earthquake On March 11, 2011, a magnitude 9.0 earthquake devastated Northeastern Japan. J-PARC (Ibaraki prefecture) suffered substantial damages to the infrastructure. Recovery is underway … could take ~12 months, but is largely unknown (=X)

3. 3 East Japan Great Earthquake On March 11, 2011, a magnitude 9.0 earthquake devastated Northeastern Japan. J-PARC (Ibaraki prefecture) suffered substantial damages to the infrastructure. Recovery is underway … could take ~12 months, but is largely unknown (=X) “So, I come with a message from the people of the United States, a message of solidarity and shared hope. Together we are looking to the future. So many U.S. companies and citizens expressed their desire to help. So our two governments, as the minister said, have agreed to create a public-private partnership for reconstruction. We wish to enhance cooperation between Japan and American businesses, between civil society groups, public officials, under the guidance of the Government of Japan, with its planning.” Hillary Clinton, Tokyo, April 17, 2011

4. 4  Hadron Facility at J-PARC  TREK Program  Search for Time Reversal Symmetry Violation  Test of Lepton Universality  Search for Heavy Neutrinos  TREK Apparatus  Status & Schedule Outline Lower intensity

5. J-PARC Facility (KEK/JAEA ） Bird’s eye photo in January of 2008 South to North Neutrino Beams (to Kamioka) JFY2009 Beams 50 GeV Synchrotron Hadron Exp. Facility Materials and Life Experimental Facility JFY2008 Beams 3 GeV Synchrotron CY2007 Beams Linac

6. 6 Beam Dump T1 target K1.8 K1.8BR K1.1 S-type KL K0.8 C-type 30~50 GeV primary beam Production target (T1)‏ Hadron Experimental Hall TREK: ~9 μA protons (270 kW) @ 30 GeV, flux ~2 x 10 6 K + /s, π/K ratio < 1

7.  K1.1BR completed in summer 2010 using the supplementary budget of FY09  Commissioned in Oct. 2010 by TREK collaboration - π/K ratio of ~1 observed - Kaon flux within expectation K0.8 Beam Line Installation K1.1-BR Proton beam Q1, Q2 D2 Q3, Q4 D1 T1 ESS Q5, Q6 D3 F Q7 Q8 MS IFX, IFY SX1 SX2 HFOC SX1

8. E06 (TREK) “ Measurement of T-violating transverse muon polarization (P T ) in K + →     decays ” Proposal to PAC 1270 kW Stage-1 approved since July 2006 E36 (Lepton Universality & Heavy Neutrino Search) “ Measurement of  (K + →e + ) /  (K + →   ) and search for heavy sterile neutrinos using the TREK detector system ” Proposal to PACs 10,1130 kW Stage-1 approval by PAC in January 2011 Planned Experiments

9. 9 CANADA University of Saskatchewan Department of Physics and Engineering University of British Columbia Department of Physics and Astronomy TRIUMF Universite de Montreal Laboratoire de Physique Nucleaire University of Manitoba Department of Physics USA Massachusetts Institute of Technology (MIT) Laboratory for Nuclear Science & Bates Linear Accelerator Center University of South Carolina Department of Physics and Astronomy Iowa State University College of Liberal Arts & Sciences Hampton University Department of Physics Jefferson Laboratory RUSSIA Russian Academy of Sciences (RAS) Institute for Nuclear Research (INR) JAPAN Osaka University Department of Physics National Defense Academy Department of Applied Physics Tohoku University Research Center for ELectron Photon Science (ELPH) High Energy Accel. Research Organzation (KEK) Institute of Particle and Nuclear Studies Institute of Material Structure Science Accelerator Laboratory Kyoto University Department of Physics Tokyo Institute of Technology (TiTech) Department of Physics VIETNAM University of Natural Sciences TREK Collaboration New collaborators are welcome!

10. 10 TREK/E06 at J-PARC http://trek.kek.jp Official website: T ime R eversal violation E xperiment with K aons: Search for New Physics beyond the Standard Model by Measurement of T-violating Transverse Muon Polarization in K +  μ + π 0 ν μ Decays

11. 11 KEK-E246: P T = - 0.0017 ± 0.0023(stat) ± 0.0011(sys) ( |P T | < 0.0050 : 90% C.L. ) ●K + ➙ π 0 μ + ν Decay at rest T-odd correlation P T ≠0 ⇒ T violation (CPT theorem) ⇒ CP violation Sakurai 1957 Transverse Muon Polarization M. Abe et al., PRL83 (1999) 4253 M. Abe et al., PRL93 (2004) 131601 M. Abe et al., PRD72 (2006) 072005

12. 12 Model K +   0  + K +   +  ■ Standard Model <10 -7 <10 -7 ■ Final State Interactions <10 -5 <10 -3 ■ Multi-Higgs  10 -3  10 -3 P T (K +   0  + )  3 P T (K +   + ) ■ SUSY with squarks mixing  10 -3  10 -3 P T (K +   0  + )  - 3 P T (K +   + ) ■ SUSY with R-parity breaking  4 x10 -4  3 x10 -4 ■ Leptoquark model  10 -2  5 x10 -3 ■ Left-Right symmetric model 0 < 7x10 -3 New Physics: Model Predictions of P T 90% C.L.

13. 13 Time Reversal Experiment with Kaons  TREK/E06: Upgrade of E246 setup  Reduce systematic error by factor ~>10 - alignment with data - correction of systematics - advanced analysis scheme  Decrease statistical error by factor ~>20 - 20x higher K + intensity at J-PARC - 10x larger polarimeter acceptance - >1.6x higher polarimeter sensitivity New Proposal of P T (K  3 ) at J-PARC 10 -4

14. Use upgraded KEK--E246 detector Active polarimeter Fiber target C0,C1 GEM CsI(Tl) readout K + →     14 The TREK Apparatus P T is measured as the azimuthal asymmetry A e + of the  + decay positrons

15.  Highly precise SM values  High sensitivity to LFV beyond SM  Current experimental precision (KLOE, NA62) Lepton universality in K l2 and  l2 decays R K SM = ( 2.477±0.001) x 10  5 R  SM = (12.352±0.001) x 10  5 R K LFV ~R K SM (1±0.013) R K =(2.487±0.013)x10  5,  R K /R K =0.52% (40% of data on tape) Improve precision to 0.24%, proposal to PAC10,11 e.g. MSSM with charged-Higgs SUSY-LFV

16. In the framework of renormalizable extension of the SM, the MSM, 3 light singlet right-handed (sterile ) are introduced The MSM can explain oscillation Light sterile play a role in Dark matter Baryon asymmetry can be induced by leptogenesis or through oscillation Measure yield and polarization for K +   + N Main background from K μ3 If the sterile is lighter than K +, K +    N could be observed. Search for heavy sterile  (N) in K +   + N Assumption: BR(K + →  N) ~10 -8 YieldPolarization

17. Target: –Finer segmentation of TGT scintillating fibers Readout: MPPC (SiPMT) or MA-PMT Particle ID: –Aerogel Cerenkov surrounding target Charged tracking: –Add new element C1 between CsI(Tl) and C2 –Add cylindrical GEM (C0) (remove aerogel) π 0 (1&2 photon) detection: –New, faster readout of CsI(Tl): APD, MAPD –Operation of wave form analysis by FADC Muon polarimeter : –Active polarimeter with increased acceptance –New muon holding field magnet with a parallel field 17 Upgrade Path LFV 30-50 kW ~2014+X TREK 270 kW >100 kW ~2015+X

18. Light guide: WLS fiber in groove of SciFi Bicron 692 WLS or Kuraray Y11 WLS Readout: SiPMT (HPK MPPC) Estimated hits in the photon sensor: ~ 7 x10 7 particles/year 3x3 mm 2 489 fibers 75mm diameter c.f. E246 Ring counters PSI FAST target Cross section Timing counters One element Active Fiber Target: Baseline Design 18 70 – 150 cm 12 fiducial counters

19. beam Target n=1.05 Fresnel mirror PID performance and detector efficiency will be controlled with K e3 and K μ3 data.  beam e/  Identification for K +  e + ν / K +   + ν  Momentum measurement of e +, μ +  TOF measurement between TOF1 and TOF2  e + trigger by aerogel Cherenkov detector  (e + from K e2 ) ~1  (  + from K  ) ~ 0.92=1/1.087 Estimated efficiency = 99.2 ± 0.2%

20. 20 TREK: Tracking Upgrade  Planar GEMs (C1) between CsI and C2  Cylindrical GEM (C0)‏ in replacement of former C1 70 µm 140 µm GEM technology: Hampton University in collaboration with MIT and Jefferson Lab

21. Improve the timing characteristics of CsI(Tl) by replacing PIN diode with APD Pulse shaping and pile-up analysis One-module energy One-module timing too slow new requirement Several tests with individual modules were done at Tohoku U. to study the performance at higher energy and high rates APD Readout for CsI(Tl)

22. 22 Active Muon Polarimeter  Full angular acceptance for positrons – 10x more than in E-246  Determination of decay vertex – background-free measurement  Measurement of e + angle and approx. energy – higher analyzing power  Improved field alignment – suppressed systematic error  Full-size prototype completed, tested at TRIUMF in Nov. 2009 μ+μ+ e+e+

23. 23  TREK at J-PARC has made substantial progress  “K1.1BR” secondary beamline has been commissioned  Measure T-violating transverse muon polarization in K μ3 decays (high power 100-270 kW, ~2015 +X) - Large potential for discovery of New Physics - Upgrade of existing experimental setup of KEK/E-246  Measure K e2 /K π2 ratio – test of lepton universality (low power 30-50 kW, ~2014 +X)  Search for heavy sterile neutrinos - Use E-246 apparatus with partial upgrades Summary New collaborators are welcome!

24. 24 Backup Slides

25. 25 C, P, and T Before 1956: All of nature’s laws invariant under Charge conjugation Parity Time reversal Right-handed antiparticle Positron or Anti-neutrino Electron or Neutrino Left-handed particle 1956-1964 Parity violated in beta decay Combination C+P good symmetry T good, CPT good 1964 until today Parity violated in weak interaction CP violated in neutral K and B weak decays CPT good All observed CP violation allowed within SM through flavor mixing Matter/Antimatter asymmetry lacks explanation Search for New Physics beyond the SM!

26. ■ Small standard model contribution – Bigi and Sanda “CP violation” (2000) – Higher-order effect – P T ~ 10 -7 ■ Small FSI spurious effects –Single photon contribution Zhitnitskii (1980) P T < ~ 10 -6 –Two photon contribution Efrosinin et al. PL B493 (2000) 293 P T ~ 4 x 10 -6 SM FSI (example) W many other diagrams vertex radiative correction Standard Model and FSI

27. 27 Typical models with scalar interactions allowing a sizable P T : –Multi-Higgs doublet model –SUSY with R-parity violation or with large squark mixing Kinematic factor Generic four-fermion interaction Lagrangian analysis Effective field theory with Wilson coefficients Exotic Scalar Interactions

28. 28 Garisto and Kane, PRD 44 (1991) 2038 Required limits for n-EDM to constrain P T : E-246/ P T < 5 x 10 -3 :→d n < 1.3 x 10 -26 e-cm TREK / P T < 3 x 10 -4 :→d n < 7.6 x 10 -28 e-cm … with m d ~ 6 MeV factor ~50 smaller, d n < 1.5 x 10 -29 e-cm! Current EDM limit d n < ~3 x 10 -26 e-cm Limit of planned n-EDM experiment ~ 2 x 10 -28 e-cm Finite P T possible within current and future n-EDM limit Neutron EDM vs P T in 3-Higgs-Doublet ≤

29. 29 TREK/E06 and E246 S |   ’  | | ’   k ’  k | (K + ) (K L ) TREK E246 SUSY with R-Parity violation E246 Result: P T = -0.0017 ± 0.0023 (stat) ± 0.0011 (sys) |P T | < 0.005: 90% C.L. TREK sensitivity: Δ|P T | < 10 -4 E246 TREK goal B→XB→X b→sb→s Neutron EDM v 2 / v 3 = m t / m  Three Higgs Doublet Model

30. 30 ● c.f. d n, b→s  ∝ Im(     *), (     *) Im(     *) = - v 2 2 / v 3 2 Im(     *) 11  E246 TREK goal B→XB→X b→sb→s Neutron EDM ● B→X  and  B→  at Super-Belle corresponds to P T < 3 x 10 -4 c.f. TREK goal : P T ≤ 1 x 10 -4 v 2 / v 3 = m t / m  P T is most stringent constraint for Im(     *)! ___ Higgs field v. e. v. Three-Higgs Doublet Model

31. 31 Super potential : W = W SMMS + W RPV Im  = Im  l + Im  d Relevant parameters and constraints TREK E246 |   ’  | | ’   k ’  k | P T is a very stringent constraint for these parameters ! SUSY with R-Parity Violation

32. Wu and Ng, Phys. Letters B392, 93 (1997) Charged Higgs exchange Constraints on Im  S, Im  P ∝  = tan  (  +A t cot  )/m g~ × Im[V 33 H+* V 32 D L * V 31 U R]/ M H 2 Im  R ∝ tan  × Im[V 33 SKM* V 33 U R * V 32 D R] / M 2 If the flavor mixing is 0(1) the transverse muon polarization can be 0(10^{-3}) |Im  | < 3.8 x 10 -2 ( E246 : 1997 ) |Im  | < 5 x 10 -4 (TREK) SUSY with Large Flavor Mixing

33. 33 Direct CP violation in K 0 system : Re(  ’/  ) = (1.66 ± 0.26)×10 -3 If this effect is due to Higgs dynamics, it has to be due to charged Higgs exchange: Because there is no  I=1/2 suppression (~ 20) in the K + system: P T ~ R × 20 = 5 × 10 -6 × 20 ~ 10 -4 -- or larger if enhanced couplings to leptons! ( I. Bigi, CERN Flavor WS, 2007 )  _  (K 0 →     ) -  (K 0 →     ) _  (K 0 →     ) +  (K 0 →     ) = (5.04 ± 0.22) ×10 -6 ≡ R ⇒ Direct CP Violation

34. 34 fwd and bwd  0 /  P T directions fwd -    bwd -    N cw - N ccw A e + = N cw + N ccw Stopped beam method (K + decay at rest) coverage of all  0 directions symmetric decay phase space Double ratio measurement small systematic errors Longitudinal field method B // P T J.A. Macdonald et al., NIM A506 (2003) 60 Features of E246

35. 35 Principle of GEM Detectors Copper layer-sandwiched kapton foil with chemically etched micro-hole pattern gas amplification in the hole GEM = Gas Electron Multiplier introduced by F. Sauli in mid 90’s, F. Sauli et al., NIMA 386 (1997) 531

36. 36 C0 Cylindrical GEM for TREK 300 mm 140 mm160 mm  Vertex tracking near target, δ < 0.1 mm  Very high rate capability 25 kHz/mm 2 (COMPASS)  Radiation-hardness 4 x10 10 MIPs/mm 2 (COMPASS)  TREK: Rates <250 Hz/mm 2 (halo <5 Hz/mm 2 ), total dose: 7 x10 7 particles

37. 300 Gauss Uniform field Well-aligned field Muon Field Magnet for TREK  Control of muon spin motion  Shielding of stray field (by iron yoke) ~0.3 G → < 0.1 G  Mechanical alignment of the 300G field →  P  ≈ 10 -3  Further alignment using K  3 data →  P ~  ≈ 10 -4