analysis strategy of high multiplicity data
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Analysis strategy of high multiplicity data
Toshiyuki Gogami24/Feb/2011
Contents
1. Introduction– Status of multiplicity and rate
2. Origin of multiplicity of HKS– Simple simulation
3. Tracking– Problems and strategy to improve– Development • DC hit wire selection with KTOF
4. Outlook & Summary
Introductions
Analysis process
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat Target
Missing Mass
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat Target
p : Λ , Σ0 ,12ΛB
Angle : Sieve slit
F2T functionF2T function
particle ID(select K+)
HKSHES
tune tune
This talk
Multiplicity of typical layer of chamberHES HKS
~1.13
~1.28
~2.24
~4.94
Multiplicity is high for HKS
Hit wires in KDC1
Overhead viewKDC1
Black : hit wires Blue : selected wiresRed : track
Black : hit wires Blue : selected wiresRed : track
CH2 52Cr
Misidentification chance in hit wires selection increase !
REAL DATA REAL DATA
low high low high
Overhead view
Singles rate summaryUp to ~30 [MHz]
Up to ~15 [MHz]HES
HKS
HKS trigger ~ 10[kHz]
HES trigger ~ a few[MHz]
COIN 2.0 [kHz]
Rate dependences
Quadratic dependence Linear dependence
• Why residuals get worse with rate (Multiplicity) ?– Hardware ?– Tracking is worse ?– Parameters ?
KTOF multiplicity ~2.7 ~1.8
~6.5 ~3.8
CH2 , 76314 52Cr , 77124Multiplicity of KDC are not only high but also TOF counters are! (for heavy target )
Origin of high multiplicity (rate) in HKS
Background event from NMR port
z [cm]
y [cm]
x [cm]
These particles come from NMR port
HKS dipole magnet
NMR port
KDC1
KDC2
KDC1
KDC2
KDC1
KDC2
KDC1
KDC2
Background events
9Be , 38.4 [μA]
9Be , 38.4 [μA] 9Be , 38.4 [μA]
Events on HKS optics
Overhead view
Side view
Β ≈ 1e- , e+
B.G. mix rate (real data)
ab
B.G mix rate =
* hks ntulpe
e+ simulation
SIMULATION
• To see 1. Number of event2. Angle & momentum
of e+ generated in target
Target thickness dependence(Simulation)
H2O52Cr9Be
12C CH2
10B
7Li
Consistent with B.G. mix rate !
SIMULATION
Angle and momentum distribution of positrons
HKS cannot accept positrons directly !
Generate these event in HKS GEANT(Next page)
SIMULATION
e , e+ background in GEANT simulation
Vacuum chamber(sus304)
NMR port(sus304)
KDC1 KDC2
e- , e+
• Generated particle : e+
• Distribution : spherical uniform• Momentum : 860 – 1000 [MeV/c]• Angle : 0 – 2 [mrad]• 1000 events
Number of e+ (Simulation) B.G. mix rate (Real data)Correlation
e+ generated in target make HKS dirty
Tracking
Basic tracking procedure
Good TDC
Pattern recognition
Track fit
Solve left right
Select good combination
Black : hit wires Blue : selected wiresRed : track
CH2 target
KDC1
52Cr target
Combination selection with TOF counters
Reduce hit wire combinations (h_tof_pre.f)
High multiplicity
Real data
New tracking scheme
Good TDC
Pattern recognition
Track fit
Solve left right
Select good combination
Combination selection with TOF counters
Reduce hit wire combinations (h_tof_pre.f)
High multiplicity
• Hit wire selection with TOF• 1X & 2X • Grouping
• Pre-PID• Cherenkov detectors
Reduce hit wires to analyze
DC hit info. selection with TOF (xx’)
Selective region Maximum gradient
Minimum gradient
Particle direction
Gravity
CUT~8%
~17%
Procedure in “h_dc_tofcut.f”1. Get KTOF1X & 2X hit counter information2. Make combination of 1X and 2X hit counter if those two are in
same group (grouping) 3. Determine cut conditions on KDC1 & KDC24. Select Hit wires in KDC and Reorder them
CUT
Just applied to xx’-layers for test
Check works of the code
• GREEN regionSelective region
• RED markersSelected hit wires
• BLACK markersRejected hit wires
Seems to work well
Particle direction
Gravity
Results of TOF cut with grouping
CH2 , 2.0 [μA] , 76315
Shift
Same
Residual
Multiplicity
CH2 , 2.0 [μA] , 76315
σ 150 [μm] σ 150 [μm]
~2.3
~1.2
before after
x x’ x x’
Result of TOF cut with groupingOriginal code
With “h_dc_tofcut.f”Pure Selective regionallowance
allowance
KDC
Too strict
select
Optimal allowance
Good tracks hid by background appear ! Number of K+ ~2[%] up
Apply to u,v-layer
Applied to uu’ and vv’ layers , too.
Selective region determined by 1X and 2X
Convert
v v’-layer
x x’-layer
Check works of the code
• GREEN region Selective region• RED markers & lines Selected hit wires• BLACK markers & lines Rejected hit wires
v v’ u u’
x x’
v v’ u u’
x x’
KDC1 KDC2particle particle
Results of TOF cut with grouping (all layers)
Residual
Multiplicity
CH2 , 2.0 [μA] , 76315
σ 150 [μm] σ 150 [μm]
Multiplicity of uu’vv’-layers• CH2
• ~20% reduction• 52Cr
• ~5-10% reduction
Same
before after
Results of TOF cut with grouping (all layers)
Faster !
Increase !TOF cut works well
52Cr
CH2
52CrFaster !
Increase !
Parameters ?
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
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
End
HKS detectors
Strangeness 2010 at KEK
K+
p, π+
Drift chambers-KDC1,KDC2-TOF walls -2X,1Y,1X-
(Plastic scintillators)
Cherenkov detectors -AC,WC-• Aerogel (n=1.05)• Water (n=1.33)
1 [m] June 2009 in JLab Hall-C
HKS trigger• CP = 1X ×1Y × 2X • K = WC × AC
CP × K
~18 [kHz](8 [μA] on 52Cr)
−π+
K+
p
σ ≈ 250 [μm]TOF σ ≈ 170 [ps]
Strangeness 2010 at KEK
HES DetectorsDrift chambers- EDC1 , EDC2 -
TOF walls - EH1 , EH2 - (Plastic scintillators)
HES D magnet
HES triggerEH1 × EH2
~2 [MHz](8 [μA] on 52Cr)e
Time Of Flight
σ ~ 300 [ps]
Target Hypernucleus Thickness[mg/cm2]
Beam Typical rateHES/HKS/COIN
[kHz]Current [μA] Total charge[C]
7Li 7He 184.0 32.0 4.84 2000 / 7 / 0.9
9Be 9Li 188.1 38.3 5.33 2400 / 9 / 1.6
10B 10Be 56.1 38.7 6.25 1300 / 1 / 0.1
12C 12B 112.5 26.8 5.90 1200 / 5 / 1.0
52Cr 52V 134.0154.0
7.6 0.835.53
2000 / 17 / 1.8
Data summary
22nd Indian-summer school (SNP2010)
Λ
Λ
Λ
Λ
Λ
E05-115 ( 2009 Aug – Nov )
Target Hypernucleus Thickness[mg/cm2]
Beam
Current[μA] Total charge[C]
CH2 Λ , Σ0 450.8 2.0 0.28
H2O Λ , Σ0 ~500.0 2.7 0.20
Physics Data
Calibration Data
(@36μA)
Analysis process
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat target
Missing Mass
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat target
p : Λ , Σ0 ,12ΛB
Angle : Sieve slit
F2T functionF2T function
particle ID(select K+)
HKSHES
tune tune
450.8 [mg/cm2]2.0 [μA]38 [hours]
σ = 2 [MeV/c2](NOT TUNED)
p(e,e’K+)Λ
p(e,e’K+)Σ0
Multiplicity and Tracking
• Tracking 1. Resolution2. Number of event
Multiplicityaffect
Strangeness 2010 at KEK
Tracking for high multiplicity
CH2 target
particleCH2 target
mean ~ 2 hit
52Cr target
mean ~ 6 hit
52Cr target
particle KDC1 trackingBlue : selected wiresBlack: hit wires
Multiplicity of typical layer
Multiplicity
Trac
king
eff.
52CrCH2
Developing new code
Traditional JLab Hall-C tracking code cannot handle with high multiplicity data.
Multiplicity of typical layer in chamber
CH2 target 52Cr target
mean ~ 6 hitmean ~ 2 hit
CH2 target 52Cr target
mean ~ 1 hitmean ~ 1 hit
106layer
6 layer6
HES
HKS Multiplicity is high in HKS
Multiplicity for each layerTarget Run Number Beam [μA] Multi
KDC1-x (@PR)
Multi KDC1-x(@N)Thickness [mg/cm2]
CH2 450.0 76314 2.0 2.92 2.72
H2O 500.0 75972 2.7 5.75 4.937Li 184.0 76220 32.0 4.26 3.85
9Be 188.1 76607 38.4 4.73 4.1610B 56.1 76184 42.4 2.52 2.4612C 112.5 76077 38.8 4.42 4.12
52Cr 154.0 77124 7.6 6.42 5.14
Angular and momentum distribution of e+
HKS should not accept e+ directory.
HKS detectors
HKS
D-m
agne
t
Multiplicity
Multiplicity is higher for heavy target
KDC wire configuration
K+
zy
x
uu’xx’
vv’ CH2 , 2.0 [μA]
52Cr , 7.6 [μA]
Multiplicity distributiony
x
Number of tracks
TOP view TOP view
KDC1
Black : hit wires Blue : selected wiresRed : track
Black : hit wires Blue : selected wiresRed : track
CH2 52Cr
Pattern recognition in KDC
KDC wire configuration
K+
zy
x
uu’xx’
vv’
y
x
x
1. Test point2. Space point
x
y
30°
90°
150°
Space point
NFOM (“h_dc_tofcut.f” for all layers)
Allowance applied to uuvv’ layers
New tracking scheme
Good TDC
Pattern recognition
Track fit
Solve left right
Select good combination
Combination selection with TOF counters
Reduce hit wire combinations (h_tof_pre.f)
High multiplicity
• Hit wire selection with TOF• 1X & 2X • Grouping
• Pre-PID• Cherenkov detectors
Reduce hit wires to analyze
2nd loop
DC hit info. selection with TOF
HitSelective region Maximum gradient
Minimum gradient
Particle direction
Gravity
CUT~8%
~17%
CUT
HTRACKING / h_dc_tofcut.f
Procedure in “h_dc_tofcut.f”1. Get KTOF1X & 2X hit counter information2. Make combination of 1X and 2X hit counter if those two are in
same group (grouping) 3. Determine cut conditions on KDC1 & KDC24. Select Hit wires in KDC and Reorder them
Just applied to x,x’-layers for test
Particle direction
Gravity