The TREK Experiment at J-PARC (Kaon 2016 Talk)
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The document discusses the TREK experiment at J-PARC, which focuses on precise measurements of the ke2/kμ2 branching ratio and explores potential new physics beyond the Standard Model. The work involves testing lepton universality, searching for dark photons, and heavy sterile neutrinos, with preliminary results presented from the E36 and E06 programs. The update covers technical aspects of the experiment, including particle identification techniques and tracking analysis, as well as future directions for further measurements and analyses.
![S. Bianchin KAON 2016 Conference (14 – 17 September 2016)
radiative corrections
helicity suppression
ge=gμ?
● In the ratio of Γ(Ke2) to Γ(Kμ2), hadronic form factors are cancelled
● Strong helicity suppression of the electronic channel enhances sensitivity
to effects beyond the SM
●
Highly precise SM prediction:
RK
SM
= (2.477±0.001) x 10-5
; δRK/RK=0.04%
[V. Cirigliano, I. Rosell, Phys. Rev. Lett. 99, 231801 (2007)]
Standard Model
4
Lepton Universality in SM for Kl2
● Radiative corrections are due to the internal Bremstrahlung part of the
radiative K e process](https://image.slidesharecdn.com/kaon2016bianchinv2-160915112201/85/The-TREK-Experiment-at-J-PARC-Kaon-2016-Talk-4-320.jpg)
![S. Bianchin KAON 2016 Conference (14 – 17 September 2016)
●
KLOE @ DANE (in-flight decay) (2009)
● NA62 @ CERN-SPS (in-flight decay) (2013)
● World Average (2013)
● Highly Precise SM value
RK
= (2.493 ± 0.025 ± 0.019) x 10-5
RK
= (2.488 ± 0.007 ± 0.007) x 10-5
RK
= (2.488 ± 0.01) x 10-5
RK
= (2.477 ± 0.001 ± 0.007) x 10-5
[V. Cirigliano, I. Rosell, Phys. Rev. Lett. 99, 231801 (2007)]
[F. Ambrosino et al., Eur. Phys. J. C64, 627 (2009)]
[C. Lazzeroni et al., PLB 719, 326 (2013)]
∆RK
/RK
≈ 0.4%
● Different systematics
- In-flight-decay experiments : kinematics overlap
- E36 stopped K+ decay experiment : detector acceptance and target interactions
● E36 proposed ∆RK
/RK
∆RK
/RK
: ≈ ± 0.20% (stat.) ± 0.15% (syst.) [0.25% total]
5
Experimental Status of RK
E36 initial aim
KLOE (2009)
NA62 (2013)](https://image.slidesharecdn.com/kaon2016bianchinv2-160915112201/85/The-TREK-Experiment-at-J-PARC-Kaon-2016-Talk-5-320.jpg)
![S. Bianchin KAON 2016 Conference (14 – 17 September 2016)
Lepton Flavor Violation in SUSY
• LFV effect may be found in RK
• RK/RK ≈ 1% corresponds to BR (--> eX ) ≤ 10-10
– Strong correlation to BR ( --> e)
– Additive to RK
SM (no interference: RK > RK
SM)
• Strong constraint on MH for large tanequalto a )
RK=RK
SM
(1+)
Yellow0.005<
Black: 0.003<<0.005
Red: 0.001<<0.003
=RK/RK
SM
Black dots: 10-9
< a< 5 x 10-9
BR (->eX) MH(GeV) MH(GeV)10-10
RK/RK
SM
tan
[ Masiero, Paradisi and Petronzio; JHEP 11 (2008) 042 ]
6](https://image.slidesharecdn.com/kaon2016bianchinv2-160915112201/85/The-TREK-Experiment-at-J-PARC-Kaon-2016-Talk-6-320.jpg)
![S. Bianchin KAON 2016 Conference (14 – 17 September 2016)
Lepton Universality Violation in Kl2
● Possible New Physics
-- MSSM with LFV
-- MSSM with R-Parity violation
-- Pseudo-scalar interaction
-- Scalar with loop correction
● SUSY with LFV for Ke2
-- Charged Higgs H+
mediated LFV SUSY
-- Large enhancement for m
2
/ me
2
-- A sizable effect up to RK
/RK
~1.3% possible
● Neutrino Mixing
-- RK
sensitive to neutrino mixing parameters within SM with 4th
generation
of quarks and leptons or sterile neutrinos
Ke2
[Masiero, P. Paradisi, & R. Petronzio, Phys Rev D74(2006) 011701, JHEP 11(2008) 042]
[J. Girrbach and U. Nierste, JHEP 05 (2010) 026; arXiv:1202.4906]
[H. Lacker and A.Menzel, JHEP 1007 (2010) 006; A. Abada et al., arXiv: 1211.3052]
7](https://image.slidesharecdn.com/kaon2016bianchinv2-160915112201/85/The-TREK-Experiment-at-J-PARC-Kaon-2016-Talk-7-320.jpg)
The TREK Experiment at J-PARC (Kaon 2016 Talk)
- 1. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Sébastien Bianchin on behalf of the TREK/E36 Collaboration The TREK Experiment at J-PARC Precise Measurement of the Ke2 /K2 branching ratio and the Search for New Physics Beyond the Standard Model (TRIUMF / University of British Columbia) 1
- 2. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) TREK program TREK = Time Reversal Experiment with Kaons E36: Test of Lepton Universality Search for dark photon Search for heavy neutrinos E06: Search for Time Reversal Symmetry Violation Lower Intensity Physics Motivation J-PARC Facility & TREK Apparatus Preliminary Results Summary & Outlook Outline 2
- 3. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) E36 (Lepton Flavor Universality) “Measurement of RK = (K+ → e+ ) / (K+ → ) and a search for dark photons & heavy sterile neutrinos” Collected data during Fall 2015; 30 - 45 kW E06 (TREK) “Measurement of the T-violating transverse muon polarization (PT) in K+ →0 decays” Stage-1 approved (July 2006), 100 - 270 kW The TREK Program E06 awaits a new beamline in the Extended Hadron Hall with higher K+ intensity 3
- 4. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) radiative corrections helicity suppression ge=gμ? ● In the ratio of Γ(Ke2) to Γ(Kμ2), hadronic form factors are cancelled ● Strong helicity suppression of the electronic channel enhances sensitivity to effects beyond the SM ● Highly precise SM prediction: RK SM = (2.477±0.001) x 10-5 ; δRK/RK=0.04% [V. Cirigliano, I. Rosell, Phys. Rev. Lett. 99, 231801 (2007)] Standard Model 4 Lepton Universality in SM for Kl2 ● Radiative corrections are due to the internal Bremstrahlung part of the radiative K e process
- 5. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) ● KLOE @ DANE (in-flight decay) (2009) ● NA62 @ CERN-SPS (in-flight decay) (2013) ● World Average (2013) ● Highly Precise SM value RK = (2.493 ± 0.025 ± 0.019) x 10-5 RK = (2.488 ± 0.007 ± 0.007) x 10-5 RK = (2.488 ± 0.01) x 10-5 RK = (2.477 ± 0.001 ± 0.007) x 10-5 [V. Cirigliano, I. Rosell, Phys. Rev. Lett. 99, 231801 (2007)] [F. Ambrosino et al., Eur. Phys. J. C64, 627 (2009)] [C. Lazzeroni et al., PLB 719, 326 (2013)] ∆RK /RK ≈ 0.4% ● Different systematics - In-flight-decay experiments : kinematics overlap - E36 stopped K+ decay experiment : detector acceptance and target interactions ● E36 proposed ∆RK /RK ∆RK /RK : ≈ ± 0.20% (stat.) ± 0.15% (syst.) [0.25% total] 5 Experimental Status of RK E36 initial aim KLOE (2009) NA62 (2013)
- 6. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Lepton Flavor Violation in SUSY • LFV effect may be found in RK • RK/RK ≈ 1% corresponds to BR (--> eX ) ≤ 10-10 – Strong correlation to BR ( --> e) – Additive to RK SM (no interference: RK > RK SM) • Strong constraint on MH for large tanequalto a ) RK=RK SM (1+) Yellow0.005< Black: 0.003<<0.005 Red: 0.001<<0.003 =RK/RK SM Black dots: 10-9 < a< 5 x 10-9 BR (->eX) MH(GeV) MH(GeV)10-10 RK/RK SM tan [ Masiero, Paradisi and Petronzio; JHEP 11 (2008) 042 ] 6
- 7. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Lepton Universality Violation in Kl2 ● Possible New Physics -- MSSM with LFV -- MSSM with R-Parity violation -- Pseudo-scalar interaction -- Scalar with loop correction ● SUSY with LFV for Ke2 -- Charged Higgs H+ mediated LFV SUSY -- Large enhancement for m 2 / me 2 -- A sizable effect up to RK /RK ~1.3% possible ● Neutrino Mixing -- RK sensitive to neutrino mixing parameters within SM with 4th generation of quarks and leptons or sterile neutrinos Ke2 [Masiero, P. Paradisi, & R. Petronzio, Phys Rev D74(2006) 011701, JHEP 11(2008) 042] [J. Girrbach and U. Nierste, JHEP 05 (2010) 026; arXiv:1202.4906] [H. Lacker and A.Menzel, JHEP 1007 (2010) 006; A. Abada et al., arXiv: 1211.3052] 7
- 8. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) J-PARC Facility (KEK/JAEA ） Bird’s eye photo in January of 2008 South to North Neutrino Beams (to Kamioka) JFY2009 Beams Hadron Exp. Facility Materials and Life Experimental Facility JFY2008 Beams 3 GeV Synchrotron CY2007 Beams Linac 8 J-PARC Facility
- 9. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Stopped K Method • K1.1BR beamline • Fitch Cherenkov • K+ stopping target Tracking • MWPC (C2, C3, C4 ） • Spiral Fiber Tracker (SFT) PID • TOF1,2; TTC • Aerogel Cherenkov (AC) • Pb glass counter (PGC) Gamma Ray • CsI(Tl) • Gap Veto (GV) Upgrade of KEK-PS E246 apparatus 9 SFT The TREK-E36 Apparatus
- 10. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) PID done with: – TOF – Aerogel Č – Lead glass (PGC) TOF Flight length 250 cm Time resolution <100 ps Mis-ID probability 7x 10-4 Aerogel Č counter TOF1 TOF2 Aerogel Č PGC Radiator thickness 4.0 cm Refraction index 1.08 e+ efficiency >98% Mis-ID probability 3% PMT Lead glass (PGC) Radiation length 1.69 cm e+ efficiency 98% Mis-ID probability 4% Target + SFT Pmis (total) = Pmis (TOF) x Pmis (AČ) x Pmis (PGC) = 8 x 10-7 < O(10-6 ) Particle Identification (+ / e+ ) + / e+ 10
- 11. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Built at TRIUMF (delivered to J-PARC in September 2014) 256 scintillating fibers (3x3 mm2 ), WLS fiber in groove MPPC readout Scintillating Fiber Target 11
- 12. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) Double-layer fibers in 2 helicities wrapped around target bundle for near target vertex Using spare MPPCs channels from fiber target 12 Spiraling Fiber Tracker (SFT)
- 13. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) CsI(Tl) Calorimeter 768 crystals e+ , μ+ Crystal length 250 mm Number of crystals 768 Segmentation 7.5° Coverage ~75% Readout PIN diodes Maximum rate ~200 kHz possible to separate with FADC has been implemented successfully Detection of photons from K+ → μ+ (e+ ) ν γ from IB+SD Detection of e+ , e- from A’ decay 13
- 14. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) 14 K-stop Blue fibers with only LG signal ● Determination of K+ stopping point and lepton depth inside the target ● Measurement of lepton emission azimuthal angle to determine SFT-Z ● Innermost element for 5-point tracking (intersection point of track and K+ cluster) ● Inclusion of LG ADC completes the target track (when HG signal is missing) Target hit pattern of a typical good event Target Tracking
- 15. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) X Y r Y z C2-G11 C2-G5 15 Tracking Analysis (Cosmic Rays & SFT)
- 16. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) 16 ● The charged particle momentum is currently determined by 4 point tracking (C2, C3, C4 MWPCs and target-xy) ● The tracking performance will be improved by introducing the 5 point tracking (C2, C3, C4, MWPCs, target, and SFT-Z) ● Events are selected by requiring track consistency with the target, SFT and TOF1 - TOF2 gap ● Monochromatic peaks due to Kμ2 and Kπ2 are clearly seen C2 C3 C4 TGT, SFT, TOF1 TOF2 K2 K2 ● The momentum resolution σ ~ 1.4% will be improved to 1% by optimizing the target energy loss correction Difference between SFT hit and track Distance between K+ vertex and track ΔZ (cm) Distance in XY (cm) p (MeV/c) Z (beam axis) (cm) R(radialdist.)(incm) PRELIMINARY PRELIMINARY Momentum Analysis
- 17. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) AC ADC PGC ADC 17 K2 K2 K2 K2 Ke3 Ke3 Ke3K2 Ke2 AC, PGC required ● Positrons are selected by AC, PGC and TOF ● PID performance by combining the three detectors is now being optimized ● Suppression of muon mis-identification below O(10-8 ) level achievable with refined analysis ● Refined analysis of PID performance in progress PRELIMINARY PRELIMINARY ● TOF time walk correction has not yet been applied Particle Identification
- 18. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) CANADA University of British Columbia Department of Physics and Astronomy TRIUMF USA University of South Carolina Department of Physics and Astronomy University of Iowa Department of Physics Hampton University Department of Physics JAPAN Osaka University Department of Physics Chiba University Department of Physics High Energy Accelerator Research Organization (KEK) Institute of Particle and Nuclear Studies RUSSIA Russian Academy of Sciences (RAS) Institute for Nuclear Research (INR) ~30 collaborators Spokesperson: S. Shimizu The TREK E36/E06 Collaboration 18
- 19. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) The TREK E36 Collaboration has completed a Lepton Universality Experiment at J-PARC NEXT Measurement of the T-violationg transverse muon polarization in K3 decay ● E06 experiment @ J-PARC (~202x) ● Requires Hadron Hall extension ● Search for dark photon / light boson ● Analysis currently in progress Calibration, CsI(Tl), PID, momentum and TOF measurements Summary and Outlook 19 ● Ke2 /K2 ratio measurement to test lepton universality with the best sensitivity available using stopped kaons
- 20. S. Bianchin KAON 2016 Conference (14 – 17 September 2016) THANK YOU! 20