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Status report - Tracking code -. T.Gogami 9/30/2010. Content. D ebug test point drift time Simulation for tracking efficiency e,e + background. T est point calculation in pattern recognition for HKS. Test point coordinate ( x , y ). y-coordinate sign is opposite !.
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Status report- Tracking code - T.Gogami 9/30/2010
Content • Debug • test point • drift time • Simulation for tracking efficiency • e,e+ background
Test point calculation in pattern recognition for HKS Test point coordinate ( x , y ) y-coordinate sign is opposite ! http://lambda.phys.tohoku.ac.jp/~gogami/HES-HKS/testpoint/testpoint.pdf But in current code • There is no affection to select space points. • But this affect in “h_tof_pre.f”. • (this case is so rare)
Clusters in residual vs. χ2 distribution Longer drift time events make clusters x’ [rad] Track χ2 x [cm] Single residual (KDC1-3) [cm] Drift time [ns]
h_tof_pre.f • pre track with space points • single hit in KTOF • multi hit in KTOF • start time calculation for drift time of chambers • correction (card)
Bugs in h_tof_pre.f start time for drift time KTOF TDC information • single hit • multi hit (mean)
Residual vs. χ2 CH2 target Current CH2 target Current Disappear clusters New CH2 target New 16 % for 52Cr target 40%
Drift distancex’ vs. residual CH2 target Current Current Residual [cm] (KDC1-3) Stripe drift distance [cm] x’ [rad] @ reference plane New New Residual [cm] (KDC1-3) drift distance [cm] x’ [rad] @ reference plane
Simulation for HKS tracking efficiency (by D.Doi) KTOF1X • input tracks in simulation ==> output file (hit wire info and so on) • input this file to real analyzer • see output tracks and compare to input tracks K+ KDC2 KDC1 one result of this simulation CH2 target Current analyzer cannot handle with high multiplicity data 52Cr target Need to improve tracking code Now developing
e,e+ b.g. in HKS TOP view 5 × 5 [cm2] Side view HKS - D HKS - Q X’ [rad] X [cm]
B.G mix rate in HKS trigger a just after pattern recognition ==>cut bad combination of space point (like h_tof_pre) ==> Saving CPU power , Reduce analysis time 52Cr (77124) b 12C (76077) 9Be (76607) 7Li (76184) . 10B (76184) B.G. mix rate = a/(a+b) ×1044 Developing B.G. cut routine
Multiplicity in chambers HES layer 10 6 after TDC cut 52Cr target CH2 target mean ~ 1 hit mean ~ 1 hit ~2 [MHz] (8 [μA] on 52Cr) HKS after TDC cut 6 6 layer 52Cr target CH2 target mean ~ 6 hit mean ~ 2 hit ~18 [kHz] (8 [μA] on 52Cr) Origin of high multiplicity is ee+ B.G. ?
Summary and to do • Summary • debug • test point calculation in “find space point” • opposite sign for y-coordinate of test point • ( finalminnum--> finalminnum+1 ) in “h_tof_pre.f” • drift time distribution got better • entry number is up (CH2:16% up , 52Cr:40% up) • Simulation for HKS tracking efficiency by D.Doi • e,e+ B.G • mix rate is high especially for 52Cr target. • need to cut before tracking • Origin of high multiplicity ? • to do • Development • reject e,e+ B.G routine • choose single hit routine --> see all combination • Check • HES side tracking code • e,e+ B.G origin ? • check ADC • Simulation
Generated e+ in Simulation pe+ : 1.2±0.5 [GeV/c] θ : 0.124±0.124 [rad] φ : 2.64159±0.5 [rad] target : 12C 100[mg/cm2] HKS D magnet HKS D magnet Splitter magnet beam: spherical uniform generation no collimator EM flag on