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電子線を用いた中重ラムダハイパー核分光 実験の 為 の 高 多重度用飛跡再現コードの開発

電子線を用いた中重ラムダハイパー核分光 実験の 為 の 高 多重度用飛跡再現コードの開発. JLab E05-115 collaboration, 2009, JLab Hall-C. Department of Science, Tohoku University Toshiyuki Gogami ( 後神 利志 ). 全体 ・ 解析 18aSG-2 川間. Contents. Experimental Setup of JLab E05-115 Motivation of Tracking C ode D evelopment

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電子線を用いた中重ラムダハイパー核分光 実験の 為 の 高 多重度用飛跡再現コードの開発

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  1. 電子線を用いた中重ラムダハイパー核分光実験の為の高多重度用飛跡再現コードの開発電子線を用いた中重ラムダハイパー核分光実験の為の高多重度用飛跡再現コードの開発 JLab E05-115 collaboration, 2009, JLab Hall-C Department of Science, Tohoku University Toshiyuki Gogami ( 後神 利志 ) 全体・解析 18aSG-2 川間 JPS 2011 autumn meeting, T.Gogami

  2. Contents • Experimental Setup of JLab E05-115 • Motivation of Tracking Code Development • New Tracking Code • Summary & outlook JPS 2011 autumn meeting, T.Gogami

  3. Contents • Experimental Setup of JLab E05-115 • Motivation of Tracking Code Development • New Tracking Code • Summary & outlook JPS 2011 autumn meeting, T.Gogami

  4. Experimental setup of JLab E05-115 Data taking : Aug-Nov 2009 p(e,e’K+)Λ HKS chamber wire configuration Tracking 2×10-4 7 [msr] 3 – 12 [deg] 2×10-4 8.5 [msr] 2 – 12 [deg] 7Li , 9Be , 10B , 12C , 52Cr ( 7ΛHe , 9ΛLi , 10ΛBe , 12ΛB , 52ΛV ) 2 - 50 [μA] 10 - 300 [THz] JPS 2011 autumn meeting, T.Gogami

  5. Contents • Experimental Setup of JLab E05-115 • Motivation of Tracking Code Development • New Tracking Code • Summary & outlook JPS 2011 autumn meeting, T.Gogami

  6. Background event of HKS REAL DATA SIMULATION 9Be , 38.4 [μA] KDC1 x [cm] H2O KDC2 y [cm] KDC1 ∝ e+ from pair creation KDC2 z [cm] ~2.24 ~4.94 JPS 2011 autumn meeting, T.Gogami

  7. Discrepancy of Number of Λ CH2 Target H2O Target Λ Λ • The number of Λ • NΛ ¼ Nexpect • The number of Λ • NΛNexpect Lost events that we are interested in in tracking procedure. Σ0 Σ0 12C quasi-free 16O quasi-free Acc. b.g. Acc. b.g. REAL DATA REAL DATA Black : hit wires Blue : selected wires Red : track Black : hit wires Blue : selected wires Red : track JPS 2011 autumn meeting, T.Gogami

  8. Contents • Experimental Setup of JLab E05-115 • Motivation of Tracking Code Development • New Tracking Code • Summary & outlook JPS 2011 autumn meeting, T.Gogami

  9. Conventional JLab Hall-Ctracking procedure Real data 52Cr target CH2 target Good TDC High multiplicity Pattern recognition Black : hit wires Blue : selected wires Red : track KDC1 Solve left right Select good combination Combination selection with TOF counters Reduce hit wire combinations (h_tof_pre.f) Track fit JPS 2011 autumn meeting, T.Gogami

  10. New tracking scheme • Hit wire selection with TOF • 1X & 2X • Grouping • Pre-PID • Cherenkov detectors Good TDC Point High multiplicity Pattern recognition Reduce hit wires to analyze Solve left right Select good combination Combination selection with TOF counters Reduce hit wire combinations (h_tof_pre.f) Track fit JPS 2011 autumn meeting, T.Gogami

  11. DC hit info. selection with TOF Gravity CUT Particle direction ~17% Selective region Maximum gradient ~8% CUT Minimum gradient JPS 2011 autumn meeting, T.Gogami

  12. Check works of the code Gravity • GREEN region Selective region • RED markers Selected hit wires • BLACK markers Rejected hit wires Particle direction JPS 2011 autumn meeting, T.Gogami

  13. Results of Introduction of new Tracking Code CH2 • NΛ¼ Nexpect  NΛ½ Nexpect Increased ! 52Cr Increased ! H2O JPS 2011 autumn meeting, T.Gogami

  14. Contents • Experimental Setup of JLab E05-115 • Motivation of Tracking Code Development • New Tracking Code • Summary & outlook JPS 2011 autumn meeting, T.Gogami

  15. Summary & outlook • Summary • JLab E05-115 ( 7ΛHe , 9ΛLi , 10ΛBe , 12ΛB , 52ΛV ) • Develop New Tracking code for high multiplicity data (H2O, 52Cr target) • NΛ ¼ Nexpect • NΛ½Nexpect • Outlook • Tracking code • Add y-position of TOF counters • Add Cherenkov information • Tracking efficiency • Parameter Optimization 全体・解析 18aSG-2 川間 JPS 2011 autumn meeting, T.Gogami

  16. END E05-115 experiment, JLab Hall-C, 2009 Thank you for your attention JPS 2011 autumn meeting, T.Gogami

  17. HKS detectors June 2009 in JLab Hall-C 1 [m] • HKS trigger • CP = 1X ×1Y × 2X • K = WC ×AC •  CP × K − π+ K+ p ~18 [kHz] (8 [μA] on 52Cr) K+ p, π+ Drift chambers -KDC1,KDC2- • Cherenkov detectors -AC,WC- • Aerogel (n=1.05) • Water (n=1.33) TOF walls -2X,1Y,1X- (Plastic scintillators) σ ≈ 200 [μm] TOF σ ≈ 170 [ps] APFB2011 in Korea (T.Gogami)

  18. HES Detectors HES D magnet Drift chambers - EDC1 , EDC2 - TOF walls - EH1 , EH2 - (Plastic scintillators) σ ~ 300 [ps] Time Of Flight HES trigger EH1 ×EH2 ~2 [MHz] (8 [μA] on 52Cr) e APFB2011 in Korea (T.Gogami)

  19. Data Summary JLab E05-115 (2009/June – 2009/Nov) APFB2011 in Korea (T.Gogami)

  20. Singles rate summary HKS Up to ~30 [MHz] HKS trigger ~ 10[kHz] HES Up to ~15 [MHz] COIN 2.0 [kHz] HES trigger ~ a few[MHz] APFB2011 in Korea (T.Gogami)

  21. Hit wires event display (2) KDC1 KDC2 v v’ v v’ uu’ uu’ • GREEN regionSelective region • RED markers & linesSelected hit wires • BLACK markers & lines Rejected hit wires particle particle x x’ x x’ APFB2011 in Korea (T.Gogami)

  22. KTOF multiplicity ~2.7 ~1.8 ~6.5 ~3.8 Multiplicity of KDC are not only high but also TOF counters are! (for heavy target ) CH2 , 76314 52Cr , 77124 APFB2011 in Korea (T.Gogami)

  23. Background event from NMR port 9Be , 38.4 [μA] 9Be , 38.4 [μA] KDC1 KDC1 x [cm] KDC2 KDC2 These particles come from NMR port Overhead view y [cm] KDC1 KDC1 KDC2 KDC2 Side view z [cm] 9Be , 38.4 [μA] HKS dipole magnet Background events Β ≈ 1 e- , e+ NMR port Events on HKS optics APFB2011 in Korea (T.Gogami)

  24. B.G. mix rate (real data) b a B.G mix rate = APFB2011 in Korea (T.Gogami) * hks ntulpe

  25. e+ simulation • To see • Number of event • Angle & momentum of e+ generated in target SIMULATION APFB2011 in Korea (T.Gogami)

  26. Target thickness dependence(Simulation) SIMULATION H2O 52Cr 9Be 12C CH2 10B 7Li Consistent with B.G. mix rate ! APFB2011 in Korea (T.Gogami)

  27. Angle and momentum distribution of positrons HKS cannot accept positrons directly ! SIMULATION Generate these event in HKS GEANT (Next page) APFB2011 in Korea (T.Gogami)

  28. e , e+ background in GEANT simulation • Generated particle : e+ • Distribution : spherical uniform • Momentum : 860 – 1000 [MeV/c] • Angle : 0 – 2 [mrad] • 1000 events e+ generated in target make HKS dirty Correlation B.G. mix rate (Real data) Number of e+ (Simulation) KDC1 KDC2 e- , e+ Vacuum chamber (sus304) NMR port (sus304) APFB2011 in Korea (T.Gogami)

  29. Apply to u,v-layer v v’-layer Selective region determined by 1X and 2X Applied to uu’ and vv’ layers , too. Convert xx’-layer APFB2011 in Korea (T.Gogami)

  30. Hit wires event display (2) KDC1 KDC2 v v’ v v’ uu’ uu’ • GREEN regionSelective region • RED markers & linesSelected hit wires • BLACK markers & lines Rejected hit wires particle particle x x’ x x’ APFB2011 in Korea (T.Gogami)

  31. Spectroscopic experiment by (e,e’K+) reaction pe’ e + p➝ e’ + K+ + Λ Feynman diagram e- e’-Spectrometer e e u u γ* K+ – γ* u s Coincidence p Missing Mass HHY d s p K+ u Λ Λ d n K+-Spectrometer pK+ target nucleus • Large Momentum transfer • Λ can be bounded in deeper orbit • Λ’s spin at forward angle • Spin flip ~ spin non-flip • Proton  Λ • Absolute mass value calibration APFB2011 in Korea (T.Gogami)

  32. JLab E05-115 experimental setup e + p → e’ + Λ + K+ 7Li , 9Be , 10B , 12C , 52Cr 2×10-4 7 [msr] 3 – 12 [deg] 2×10-4 8.5 [msr] 2 – 12 [deg] • (e,e’K+) experiment • Coincidence experiment (K+ and e-) • Small cross section ( ~100 [nb/sr] ) 1/1000 • Energy resolution Sub MeV (FWHM) • Primary beam • High intensity • Thin target (~100 [mg/cm2]) • High quality APFB2011 in Korea (T.Gogami)

  33. JLab CEBAF ( Continuance Electron Beam Accelerator Facility ) • Requirements for accelerator • High duty factor (~100%) • High intensity ( >a few 10 μA ) • Smallemittance ( ~2 [mm・μrad] ) • Small ΔE/E ( <1×10-4 ) • (e,e’K+) experiment • Coincidence experiment (K+ and e-) • Small cross section ( ~100 [nb/sr] ) 1/1000 • Energy resolution sub MeV (FWHM) 100 [m] CEBAF was unique facility before MAMI updated Experimental Hall APFB2011 in Korea (T.Gogami)

  34. Coincidence time vs. Mass square APFB2011 in Korea (T.Gogami)

  35. Cherenkov cut APFB2011 in Korea (T.Gogami)

  36. Cherenkov light APFB2011 in Korea (T.Gogami)

  37. HESの構成

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