status report - tracking code -
DESCRIPTION
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 !. - PowerPoint PPT PresentationTRANSCRIPT
Status report- Tracking code -
T.Gogami9/30/2010
Content
• Debug– test point– drift time
• Simulation for tracking efficiency• e,e+ background
Test point calculation in pattern recognition for HKS
y-coordinate sign is opposite !
http://lambda.phys.tohoku.ac.jp/~gogami/HES-HKS/testpoint/testpoint.pdf
Test point coordinate ( x , y )
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
x [cm]
x’ [r
ad]
Single residual (KDC1-3) [cm]
Trac
k χ2
Drift time [ns]
Longer drift time events make clusters
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.fstart time for drift timeKTOF TDC information– single hit– multi hit (mean)
Residual vs. χ2CH2 target
CH2 target
Current
New
Current
New
CH2 target
16 %
for 52Cr target40 %
Disappear clusters
Drift distancex’ vs. residual
x’ [rad] @ reference plane
Resi
dual
[cm
] (KD
C1-3
)
x’ [rad] @ reference plane
Resi
dual
[cm
] (KD
C1-3
)
drift distance [cm]
drift distance [cm]
Current
New New
Current
Stripe
CH2 target
CH2 target
52Cr target Need to improve tracking code
K+
KDC1
KDC2
KTOF1X
Now developing
Current analyzer cannot handle
with high multiplicity data
1. input tracks in simulation ==> output file (hit wire info and so on)
2. input this file to real analyzer
3. see output tracks and compare to input tracks
Simulation for HKS tracking efficiency (by D.Doi)
one result of this simulation
e,e+ b.g. in HKSTOP view
Side view
X [cm]
X’ [r
ad]
5 × 5 [cm2]
HKS - DHKS - Q
B.G mix rate in HKS trigger
just after pattern recognition==>cut bad combination of space point (like h_tof_pre)==> Saving CPU power , Reduce analysis time
52Cr (77124)
12C (76077)
9Be (76607)10B (76184)7Li (76184) .
×1044
a
b
B.G. mix rate = a/(a+b)
Developing B.G. cut routine
Multiplicity in chambers
CH2 target 52Cr targetmean ~ 6 hitmean ~ 2 hit
CH2 target 52Cr targetmean ~ 1 hitmean ~ 1 hit
106layer
6 layer6
HES
HKS
Origin of high multiplicity is ee+ B.G. ?
after TDC cut
after TDC cut
~2 [MHz](8 [μA] on 52Cr)
~18 [kHz](8 [μA] on 52Cr)
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 magnetHKS D magnet
Splitter magnet
beam:spherical uniform generation
no collimatorEM flag on