1 / 21

J-PARC E06 K + →π 0 μ + ν(Kμ3) を用いた 時間反転非保存探索実験における 新型光センサーの活用法

Dec 8, 2006 第 2 回次世代光センサーに 関するワークショップ. J-PARC E06 K + →π 0 μ + ν(Kμ3) を用いた 時間反転非保存探索実験における 新型光センサーの活用法. 清水俊 大阪大学理学研究科. Transverse muon polarization. K + → p 0 m + n decay. T-odd. Spurious effects from final state interaction are small. Non-zero P T is a signature of T violation.

echo-mcguire
Download Presentation

J-PARC E06 K + →π 0 μ + ν(Kμ3) を用いた 時間反転非保存探索実験における 新型光センサーの活用法

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dec 8, 2006 第2回次世代光センサーに 関するワークショップ J-PARC E06 K+→π0μ+ν(Kμ3)を用いた時間反転非保存探索実験における新型光センサーの活用法 清水俊 大阪大学理学研究科

  2. Transverse muon polarization K+→p0m+ndecay T-odd • Spurious effects from final state interaction are small.Non-zero PTis a signature of T violation. • Clear channel to search for T violation. Long history of theoretical and experimental studies. (J.J. Sakurai, 1957) • Experiment at KEK(E246) PT = - 0.0017 ± 0.0023(stat) ± 0.0011(syst) ( |PT| < 0.0050 : 90% C.L. ) PRD73, 72005(2006)

  3. Matrix element of K+→p0m+n decay Im(ξ)≠0 T-violation T-violation parameter : Im(ξ) PT is sensitive to scalar couplings.

  4. Theoretical aspects • Standard Model contribution to PT: • Only from vertex radiative corrections andPT(SM) < 10-7 • Spurious effects from final state interactions (FSI): PT(FSI) < 10-5 • There is a large window for new physics beyond the SM in the region of PT = 10-3 ~ 10-5 • There are theoretical models which allow sizeable PT without conflicting with other experimental constraints. • Multi-Higgs doublet (3 Higgs doublet) model (MH) • SUSY with s-quark mixing (SUS) • SUSY with R-parity violation (SUR)

  5. KEK-12GeV PS KEK 全体図

  6. T-violation search in KEK E246 experiment decay • Stopped K+ method • Large solid angle and high resolution of Toroidal Spectrometer and CsI(Tl) calorimeter end view side view

  7. Experimental setup

  8. Determination of PT Stopped K+ beam Double ratio measurement • ＋PT(π0 forward)＝－PT(π0 backward) • PN contribution to systematic error is • drastically reduced. Stopped K+のためtargetと、 fwd/bwd π0検出器 が重要な鍵となる。

  9. K+静止用ターゲット • K+静止崩壊用ターゲット • 直径8cmのプラスティック • ２５6本のシンチレーションファイバーで構成 • 読み出し：PMT（浜松H1635) • K+ 崩壊位置を特定する

  10. Pπ 測定 Using Stopped K+ measurement of Pπ, Pμ,Sμ • Pπ：　CsI(Tl) calorimeter not only 2 γ but also 1 γ with high energy σ＝１４MeV

  11. Segmentation Dq= Df= 7.5o Number of crystals 768 Length of crystals 25 cm (13.5 X0) Inner radius 20 cm Outer radius 50 cm Solid angle ~75%of 4p Readout PIN diode Light yield 11000 p.e./MeV Equiv. noise level 65 keV ΔE/E 12-14% at 1257 keV(22Na) σE 3% at 200MeV • D.V.Dementyev et al. Nucl. Instr. Method A440 (2000) 151 CsI(Tl) photon detector • Pin diode使用により、 • 　強磁場での利用可能 • 　省スペース化

  12. E246 result • AT = (Afwd-Abwd) / 2 • Ncw-Nccw • Afwd(bwd) = • Ncw-Nccw • PT = AT / {a <cosqT>} • a : analyzing power • <cosqT> : attenuation factor • Imx = PT / KF • KF :kinematic factor PT = - 0.0017 ± 0.0023(stat) ± 0.0011(syst) ( |PT | < 0.0050 : 90% C.L. ) Imx = - 0.0053 ± 0.0071(stat) ± 0.0036(syst) ( |Imx | <0.016 : 90% C.L. ) Statistical error dominant

  13. New experiment at J-PARC • We aim at a sensitivity of dPT ~10-4 (E246-dPT ~10-3) • Statistical errordPTstat ≤0.1 dPTstat (E246) ~10-4 with 1) ×30 of beam intensity, 2) ×10 ofdetector acceptance, and • higher analyzing power Systematic error dPTsyst ~ 0.1 dPTsyst (E246) ~10-4by 1) precise calibration of misalignments using data 2) correction of systematic effects JPARC

  14. J-PARC 施設 Parameters of Main Ring Extraction Beam Energy50 GeVAverage Beam Current15 μARepetition0.3 HzExtraction SchemeFast, and Slow

  15. Upgrade of the detector • Muon polarimeter passive → active • Muon magnetic field toroid → muon field magnet • Target smaller and finer segmentation • Charged particle tracking addition of two chambers • CsI(Tl) readout PIN diode → APD • New analysis scheme

  16. Target • Smaller size (smaller beam spot) • Finer segmentation • Sci. fiber of 20 cm length • Clear fiber or direct attachment • Light readout by SiPMTs Diameter 6 cm Active length 20 cm Fiber size 2.5×2.5 mm No. of fibers 432 Light readout 4 clear fibers Light yield ~ 10/SiPMT

  17. Target and tracking • Addition of C0 and C1 • GEM chambers with • -high position resolution • - higher rate performance • Larger C3-C4 • distance • Use of He bags E246 J-PARC • Better kinematical resolution • Stronger Kp2difm+ BG suppression • New target

  18. CsI(Tl) readout • CsI(Tl) + APD+ Amplifier + FADC • Electrons after APD : ~ 2 ×107 @ 100 MeV • Max count rate / module : ~ 100 kHz • Max K+ decay rate : ~ 20 MHz - enough for the beam intensity in Phase 1 • Noise level : to be tested • Module energy resolution : to be tested • Energy resolution is determined by lateral shower • leakage

  19. Sensitivity estimate Statistical sensitivity Systematic errors Source dPT dz < 10-4 qz < 10-4 qe+, Ee+ < 10-4 Source dPT • Net run time 1.0 ×107 s • Proton beam intensity 9mA on T1 • K+ beam intensity 3×106 /s • Total number of good Km3 2.4×109 • Total number of fwd/bwd (N) 7.2×108 • Sensitivity coefficient 3.73√N Total ~ 10-4 Total ~ 10-4 JPARC

  20. Summary • PT in Km3 is a very sensitive probe of new physics • We propose a J-PARC experiment in the early stage of Phase 1 to pursue a limit of dPT ~ 10-4. • K0.8 beamline as a branch of K1.1 • Upgraded E246 detector • Beam time request = 1.3×107 s (net) at Ip= 9mA on T1 • We would like to take the first step this year toward • Collaboration forming • Fund application • Detector R&D after obtaining some status.

More Related