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Analysis strategy of high multiplicity data

Analysis strategy of high multiplicity data. Toshiyuki Gogami 24/Feb/2011. Contents. Introduction Status of multiplicity and rate Origin of multiplicity of HKS Simple simulation Tracking Problems and strategy to improve Development DC hit wire selection with KTOF

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Analysis strategy of high multiplicity data

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  1. Analysis strategy of high multiplicity data Toshiyuki Gogami 24/Feb/2011

  2. Contents • Introduction • Status of multiplicity and rate • Origin of multiplicity of HKS • Simple simulation • Tracking • Problems and strategy to improve • Development • DC hit wire selection with KTOF • Outlook & Summary

  3. Introductions

  4. Analysis process HES This talk HKS tracking tracking x , x’ , y , y’ at Reference plane x , x’ , y , y’ at Reference plane F2T function F2T function x’ , y’ , p at Target x’ , y’ , p at Target particle ID (select K+) Missing Mass tune tune p : Λ , Σ0 ,12ΛB Angle : Sieve slit

  5. Multiplicity of typical layer of chamber HES HKS ~1.13 ~2.24 ~4.94 ~1.28 Multiplicity is high for HKS

  6. Hit wires in KDC1 KDC1 Overhead view Overhead view Misidentification chance in hit wires selection increase ! low high low high REAL DATA REAL DATA Black : hit wires Blue : selected wires Red : track Black : hit wires Blue : selected wires Red : track CH2 52Cr

  7. 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]

  8. Rate dependences • Why residuals get worse with rate (Multiplicity) ? • Hardware ? • Tracking is worse ? • Parameters ? Linear dependence Quadratic dependence

  9. 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

  10. Origin of high multiplicity (rate) in HKS

  11. 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

  12. B.G. mix rate (real data) b a B.G mix rate = * hks ntulpe

  13. e+ simulation • To see • Number of event • Angle & momentum of e+ generated in target SIMULATION

  14. Target thickness dependence(Simulation) SIMULATION H2O 52Cr 9Be 12C CH2 10B 7Li Consistent with B.G. mix rate !

  15. Angle and momentum distribution of positrons HKS cannot accept positrons directly ! SIMULATION Generate these event in HKS GEANT (Next page)

  16. 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)

  17. Tracking

  18. Basic tracking 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

  19. New tracking scheme • Hit wire selection with TOF • 1X & 2X • Grouping • Pre-PID • Cherenkov detectors Good TDC 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

  20. DC hit info. selection with TOF (xx’) Just applied to xx’-layers for test Gravity CUT Particle direction ~17% Selective region Maximum gradient ~8% CUT Minimum gradient Procedure in “h_dc_tofcut.f” Get KTOF1X & 2X hit counter information Make combination of 1X and 2X hit counter if those two are in same group (grouping) Determine cut conditions on KDC1 & KDC2 Select Hit wires in KDC and Reorder them

  21. Check works of the code Gravity • GREEN region Selective region • RED markers Selected hit wires • BLACK markers Rejected hit wires Particle direction Seems to work well

  22. Results of TOF cut withgrouping Residual before after CH2 , 2.0 [μA] , 76315 Same σ 150 [μm] σ 150 [μm] Multiplicity CH2 , 2.0 [μA] , 76315 x’ x’ x x Shift ~1.2 ~2.3

  23. Result of TOF cut withgrouping Original code KDC allowance select Pure Selective region allowance With “h_dc_tofcut.f” Optimal allowance Number of K+ ~2[%] up Good tracks hid by background appear ! Too strict

  24. 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

  25. Check works of the code 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’

  26. Results of TOF cut withgrouping (all layers) Residual before after CH2 , 2.0 [μA] , 76315 σ 150 [μm] σ 150 [μm] Same Multiplicity • Multiplicity of uu’vv’-layers • CH2 • ~20% reduction • 52Cr • ~5-10% reduction

  27. Results of TOF cut withgrouping (all layers) CH2 TOF cut works well Faster ! Increase ! 52Cr Faster ! 52Cr Increase ! Parameters ?

  28. Outlook • Tracking • HKS • Pre-PID before pattern recognition of KDC • Rough cut of π+ , p , e with Cherenkov • Improvement of hit wire combination selection • Still we have β 1 background particles • Optimize TDC and ADC cut • Reduce KTOF multiplicity  DC hit wire selection with TOF should be better. • HES • Parameter check • Different parameters should be used for heavy target

  29. Summary • Status of Multiplicity and rate • Higher in HKS than HES • Strongly dependent on target in HKS • Origin of high multiplicity and rate • Should be e- , e+ • Because of simulation results and its beta • Development of Tracking for high multiplicity target • TOF cut with grouping works well • Analysis time is faster by 10%. • Multiplicity is decreased by 5~50%. • Number of K+ is increased by 25% for 52Cr target. • Residual is still bad for 52Cr. Need to study

  30. End

  31. 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 ≈ 250 [μm] TOF σ ≈ 170 [ps] Strangeness 2010 at KEK

  32. 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 Strangeness 2010 at KEK

  33. E05-115 ( 2009 Aug – Nov ) Data summary Physics Data Λ Λ Λ Λ (@36μA) Λ Calibration Data 22nd Indian-summer school (SNP2010)

  34. Analysis process HES HKS tracking tracking x , x’ , y , y’ at Reference plane x , x’ , y , y’ at Reference plane 450.8 [mg/cm2] 2.0 [μA] 38 [hours] p(e,e’K+)Λ p(e,e’K+)Σ0 σ = 2 [MeV/c2] (NOT TUNED) F2T function F2T function x’ , y’ , p at target x’ , y’ , p at target particle ID (select K+) Missing Mass tune tune p : Λ , Σ0 ,12ΛB Angle : Sieve slit

  35. Multiplicity and Tracking • Tracking • Resolution • Number of event Multiplicity affect

  36. Tracking for high multiplicity 52Cr target CH2 target particle KDC1 tracking particle Blue : selected wires Black: hit wires mean ~ 2 hit mean ~ 6 hit CH2 target 52Cr target Multiplicity of typical layer Traditional JLab Hall-C tracking code cannot handle with high multiplicity data. Tracking eff. CH2 52Cr Developing new code Multiplicity Strangeness 2010 at KEK

  37. Multiplicity of typical layer in chamber layer 10 6 52Cr target CH2 target mean ~ 1 hit mean ~ 1 hit HES 6 6 layer 52Cr target CH2 target mean ~ 6 hit mean ~ 2 hit HKS Multiplicity is high in HKS

  38. Multiplicity for each layer

  39. Angular and momentum distribution of e+ HKS should not accept e+ directory. HKS detectors HKS D-magnet

  40. Multiplicity KDC wire configuration Multiplicity is higher for heavy target v’ CH2 , 2.0 [μA] K+ v 52Cr , 7.6 [μA] x’ x u’ z y u Multiplicity distribution x y x

  41. Number of tracks KDC1 TOP view TOP view Black : hit wires Blue : selected wires Red : track Black : hit wires Blue : selected wires Red : track CH2 52Cr

  42. Pattern recognition in KDC Space point KDC wire configuration v’ 150° K+ v x’ 90° x x y Test point Space point u’ z y 30° u x y x x

  43. NFOM (“h_dc_tofcut.f” for all layers) Allowance applied to uuvv’ layers

  44. New tracking scheme 2nd loop • Hit wire selection with TOF • 1X & 2X • Grouping • Pre-PID • Cherenkov detectors Good TDC 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

  45. DC hit info. selection with TOF Particle direction Gravity CUT Hit ~8% ~17% Selective region Maximum gradient CUT Minimum gradient

  46. HTRACKING / h_dc_tofcut.f Particle direction Gravity Just applied to x,x’-layers for test Procedure in “h_dc_tofcut.f” Get KTOF1X & 2X hit counter information Make combination of 1X and 2X hit counter if those two are in same group (grouping) Determine cut conditions on KDC1 & KDC2 Select Hit wires in KDC and Reorder them

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