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Simulation activities in India: students working on various topics.. Partha(VECC), Hemen (GU) : Trigger, SIS100, physics simulation Bipasha (CU): dynamic range simulation, J/Psi physics at FAIR Arun: Geometry study Manish, Irshad (Jammu U) - PowerPoint PPT Presentation
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Simulation activities in India:
students working on various topics..
Partha(VECC), Hemen (GU) : Trigger, SIS100, physics simulation Bipasha (CU): dynamic range simulation, J/Psi physics at FAIR Arun: Geometry study Manish, Irshad (Jammu U)
EVO meet every Thursday: co-ordinator: Z. Ahammed
9th September,2009 CBM-Muon Meeting(EVO) 2
Study of Manual Segmentation of
MuCh
ARUN PRAKASH
High Energy Physics Lab
Department of Physics
Banaras Hindu University
Varanasi-221005
9th September,2009 CBM-Muon Meeting(EVO) 3
Outline
Manual Segmentation Study
Results
Future Plan
Approach:
Reduce total no of pad sizes to 0.5 Milion
Single track (and muon) efficiency should not change with highest granularity case
9th September,2009 CBM-Muon Meeting(EVO) 5
Standard Geometry Cbmroot trunk
version Embedded 1000
central events Au+Au at 25 AGeV
Standard MuCh: 13 layers
Total length : 3.4m
9th September,2009 CBM-Muon Meeting(EVO) 6
Manual Segmentation
A.2x.4 to
1.6 x 3.2
3 regions
Rest all: 1.6 x 1.6
1 region
Total no of pads: 577536
9th September,2009 CBM-Muon Meeting(EVO) 7
Manual Segmentation(contd...)
B.2 x .4
One region Rest all 1.6 x 1.6 (one region each)
No of pads:No of pads:
12113921211392
9th September,2009 CBM-Muon Meeting(EVO) 8
Manual Segmentation(contd...)
C2 regions:
.2 x .4
.4 1.6Rest 1.6 x 1.6.
1 region
No of pads: 628736
9th September,2009 CBM-Muon Meeting(EVO) 9
Manual Segmentation(contd...)
D3 regions:
.2 x .4
to.8 x 3.2 Rest:
1.6 x 1.6, one region
Total no of pads: 574464
9th September,2009 CBM-Muon Meeting(EVO) 10
Manual Segmentation(contd...)
E3 regions:
.2 x .4 to
1.6 to 3.2
3 regions:
.8 x 1.6 to
3.2 to 3.2
2 regions:
1.6 x 3.2 to
3.2 to 3.2
Rest 3.2 x 3.2
Total no of pads:
195840
9th September,2009 CBM-Muon Meeting(EVO) 11
Efficiency of Muons(standard geo)Presented earlier
Why no change in efficiency?Can we work with largest pad size?
Take one region/station, double pad size for
every subsequent stationChange track selection criteria and see the effect
Manual Segmentation
STATION PAD SIZE(cm)
1 2 3 4 5 6
A 0.25x0.25 0.45x0.45 0.6x0.6 0.8x0.8 1.25x1.25 1.25x1.25
B 0.5x0.5 0.9x0.9 1.2x1.2 1.6x1.6 1.6x1.6 2.5x2.5
C 1.0x1.0 1.8x1.8 2.4x2.4 3.2x3.2 3.2x3.2 5.0x5.0
D 5.0x5.0 6.0x6.0 7.0x7.0 8.0x8.0 9.0x9.0 10.0x10.0
4 different pad sizesPAD SIZE (1st)PARAMETERS
0.25X0.25(A) 0.5X0.5(B) 1X1(C) 5X5(D)
# of Digis 2210 2191 2060 1113
# of Global track 2335 2401 2925 5130
# of Much Track 1994 2086 2649 4962
(8hits)Eff (STS+MUCH)
0.94 0.94 0.94 0.77
(6hits)Eff(STS+MUCH)
0.84 0.84 0.84 0.73
Eff(10hits)(STS+MUCH)
0.89 0.89 0.89 0.89
Total no of pads 2,400,480 691,040 170,376 15,768
9th September,2009 CBM-Muon Meeting(EVO) 15
Future Plan
To look into other parameters like invariant
mass, acceptance plot,momentum distribution
etc.
Add clustering
Study auto-segmentation
Dynamic Range of Much
Bipasha BhowmickUniversity of Calcutta, Kolkata
& Partha Pratim Bhaduri,VECC,Kolkata
● DYNAMIC RANGE DYNAMIC RANGE
It is a term used frequently in numerous fields to
describe the ratio between the smallest & largest
possible values of a changeable quantity (such as
measurable deposited energy)
Aim & algorithm
Dynamic range is a quantity essential for design of the read-out chips.
Determination of the energy deposition at each cell of the muon chambers ( in terms of MIP ,as muons give MIP signal).
Take different cell sizes (2mm. – 4cm.) & find out the fraction of multiple-hit cells & singly-hit cells for particles generated by UrQMD.
Optimize the cell size based on multi-hit fraction.
For the optimal cell size find cell energy deposition (E_dep) both for single muons (MIP spectra) & UrQMD particles.
Apply different MIP cuts & calculate the loss due to saturation.
Apply different hit cuts to observe the effect on tracking.
Fraction of multiple-hit cells= (total # of cells having >1 hit)/ (total # of cells hit)
Optimal cell-size : 4mm. for inner stations, 4cm. For outer stations (stn 12 onwards)
Single muon energy deposition spectra :Fitted with Landau distributionMIP value : 0.197 KeV (MPV of the Landau)
Station# 1Cell size : 4mm.
Station# 12Cell size: 4cm.
E_dep by UrQMD particles
Station# 1Cell size : 4mm.
Station# 12Cell size: 4cm.
Saturation loss : part of the energy spectra above the selected energy deposition cut (in terms of MIP) valueMIP cut: E_dep cut (keV)/MIP value(= 0.197 keV)
OBSEVATIONnumber of tracks is affected to a permissible
amount(2.78% of the total tracks) if we reject 2% of
the total hit in each station
• Statistics :
• UrQMD : 50 central events
• Single muons : 50 events with
50 mu+ & 50 mu- in the
momentum range 2.5GeV-
25GeV generated at angle 2.5
to 25 degree using box-
generator
Comparison of percentage of track lost using Comparison of percentage of track lost using
different signals as inputdifferent signals as input
signal-1. hit loss track loss 5% 6.76%
10% 18.55%
signal-2. 5% 7.58%
10% 19.1%
signal-3. 5% 7% 10% 19.16%
Varying the number of muon tracks added in embedding
Trigger simulation
Partha Pratim BhaduriVECC, India
CbmRoot Version: Trunk version
Much geometry : Standard Geometry
• 2 layers in 5 stations
• Distance between layers 10 cm.
• Gap between absorbers 20 cm
• 3 layers at the last trigger station
• Total 13 layers
• Total length of Much 350 cm
Signal : J/ decayed muons from Pluto
Background : minimum bias UrQMD events for Au+ Au at 25 GeV/n
Much Hit producer w/o cluster & avalanche
L1(STS) & Lit (Much) tracking with branching
Input : reconstructed Much hits
Simulation
Absorber thickness (cm):20 20 20 30 35 100
Trigger algorithm
• Take 3 hits from the trigger station with one from each of the 3 layers & fit with st. line both in X-Z & Y-Z plane passing through the origin (0. 0) i.e.
X = m0*Z ; Y=m1*Z Make all possible combinations• Find 2 & apply cut on both 2
X &2y
• Hit combination satisfying the cuts is called a triplet.
• Hits once used for formation of a triplet is not used further.
• Find m0 & m1 of the fitted st. lines
• Define a parameter α=√(m02+m1
2)• Apply cut on α
Magnetic field
(0,0,0)(0,0.0)
11 12 13
Trigger station
Specification of cuts
Cut 1: at least 1 triplet/event
Cut 2 : at least 2 triplets/event
Cut 3 : at least one of the selected triplets satisfy alpha cut
Cut 4 : at least two of the selected triplets satisfy alpha cut
Events analyzed: 80k minimum bias UrQMD event for background suppression factor & 1k embedded minimum bias events for J/ reconstruction efficiency
Event
Input
Cut-1
Cut-2 Cut-3
cut-4
Pluto 10k 7941 2964 2570 1487
UrQMD 80k 2624 255 91 56
Event selection
Set : 1
Cut Values :
2x,y<=0.2
α>=0.183
Background suppression factor (B. S. F)
Cut Events survived
Statistical Error
B. S. F
1 2624 1.95 % ~ 30
2 255 6.26 % ~314
3 91 10.4 % ~879
4 56 13.36 % ~1430
B. S. F = Input events (80,000) / events survived
Reconstructed J/
Trigger cut Reconstruction efficiency (%)
no cut 29.3 %
Cut 1 29.2 %
Cut 2 24.5 %
Cut 3 24.2 %
Cut 4 15.3 %
1k embedded minimum bias events
Trigger Cut 1 (Reconstructed J/ : 292)
Trigger Cut 2 (Reconstructed J/ : 245)
Trigger Cut 3 (Reconstructed J/ : 242)
Trigger Cut 4 ( Reconstructed J/ : 153)
Observation
• Hit-triplets are made from last 3 layers of the trigger station, vertex included in the fitting.
• Systematic study of background suppression & number of reconstructed J/y & its phase space distribution on cut by cut basis has been done. Statistics will be increased to reduce the statistical error further.
Using information from “Much-only” gives sufficient B. S.F (~1430).
With the application of the 4th trigger cut there is a decrease in signal reconstruction efficiency up to ~ 50 %
Cut by cut investigation shows even up to the 3rd trigger cut we have reasonable B. S. F (~879) but without decrease in signal reconstruction efficiency.
Phase space distribution of the triggered & un-triggered sample shows that all the trigger cuts are unbiased.
Future Plans
Prepare a look-up table for different values of cut parameters &
corresponding values of B. S.F & signal reconstruction efficiency.
Implementation of TRD in the present scheme.
Study pad resolution effect.
Formation of CbmMuchTrigger class to be run in chain.
SIS-100 simulation
We have a HSD version with charm production,
we are running that for generation of signal for
SIS100
Will vary muon geometry (no of stations/pad-
sizes)
Arun (and Dr. Viyogi) will be at GSI working on
this
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