EMU Trigger Simulations
Darin Acosta
DOE/NSF Review
February 17, 1999
US CMS DOE/NSF Review: February 17-19, 1999
1
CSC and DT Layout
Overlap
1.2 > η > 0.9
DT
η = 0.5
η = 1.1 η = 1
MB/1/4
MB/2/4
YB/1/3
YB/2/3
ME/1/3
7.380 m
7.000 m
MB4
5.975 m
MB3
4.905 m
MB2
YB/0/3
MB/1/3
MB/0/3
YB/2/2
YB/1/2
YB/0/2
MB/2/2
YB/2/1
MB/1/2
YB/1/1
MB/0/2
YB/0/1
MB/2/1
MB/1/1
MB/0/1
ME/1/2
ME/2/2
MB/2/3
4.020 m
3.800 m
MB1
CB/0
2.950 m 2.864 m
2.700 m
ME/1/1
YE/1
HB/1
1.9415 m
HE/1
1.711 m
HF/1
1.811 m
EB/1
EE/1
η = 3.0
ME/2/1
ME/3/1
ME/4/1
4
YE/2
η = 2.
YE/3
10.86 m
CSC
ME/3/2
ME/4/2
η = 1.479
MB/0/4
1.290 m 1.185 m
SB/1
0.440 m
η = 5.31
0.00 m
ME3 ME2
US CMS DOE/NSF Review: February 17-19, 1999
ME1
0.000 m
2.935 m
3.90 m
4.332 m
5.68 m
6.66 m
6.45 m
7.24 m
8.495 m
9.75 m
10.83 m
10.63 m
10.91 m
14.53 m
14.96 m
14.56 m
SE/1
CMS - PARA- 003 - 14/10/97
PP
/pg/hr
2
Muon Flux dN/dPtdηdt (Hz/GeV)
Estimated Muon Flux
• Estimate muon flux at
L=1034 from QCD events
All µ
10 6
10
• Parameterization based on
Pythia (CMS Note 1997/096)
• Includes π/K which decay
before calorimeter
µ from π/K
5
µ from b/c
10 4
10 3
10 2
• Fold in probability to
punch through calorimeter
in endcap region
10
1
10
10
10
-1
• Determined from CMSIM
-2
-3
1
10
PT (GeV/c)10
US CMS DOE/NSF Review: February 17-19, 1999
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• Assume 100% chamber
efficiency
3
Trigger Efficiency Curves
Efficiency
• Convolute muon flux with trigger efficiency
curve to determine trigger rate
• Assume Gaussian errors for 1/PT resolution
10% resolution
50% resolution
Large rate here
Threshold
US CMS DOE/NSF Review: February 17-19, 1999
True PT (GeV/c)
4
Muon Rate dN/dηdt (Hz)
CSC Muon Trigger Rates
10 7
10
34
• Single µ rate from
Pythia, convoluted
with efficiency curve
-2 -1
L = 10 cm s
6
10 5
50%
10 4
40%
10 3
10 2
30%
• Require rates < 1 kHz
per unit rapidity
10
1
10
10
• Thresholds set for
90% efficiency
20%
CSC resolution from CMSIM
-1
10% resolution
-2
1
PYTHIA6
10
10
2
Effective PT Threshold (GeV/c)
US CMS DOE/NSF Review: February 17-19, 1999
• Not satisfied for PT
resolution worse than
30%
5
CMSIM Study of CSC
Trigger Resolution
7.5
5
2.5
0
5
2.5
0
1
0
-1
-2.5
1
2
1
ηgen
3
Φ1-Φ3 (degree)
Φ1-Φ2 (degree)
7.5
2
1
2
ηgen
3
Φ2-Φ3 (degree)
-2.5
Φ2-Φ3 (degree)
Φ1-Φ3 (degree)
Φ1-Φ2 (degree)
• Study dependence of
∆ϕ on η and PT
2
1
1
2
1
2
1
2
ηgen
• ϕ and η from LCT
trigger simulation of
single µ’s with no
backgrounds
0.4
0.2
0
2
ηgen
0.4
0.3
0.2
0.1
0
1
2
ηgen
0.4
Φ2-Φ3 (degree)
1
0
Φ1-Φ3 (degree)
Φ1-Φ2 (degree)
0
0.3
0.2
0.1
0
1
2
ηgen
ηgen
0.4
0.3
0.2
0.1
0
1
2
ηgen
US CMS DOE/NSF Review: February 17-19, 1999
ηgen
6
Parameterize ∆ϕ vs
vs.. PTT and η
• Fit to ∆ϕ = A(η)/ PT
• Invert relation to
obtain PT
US CMS DOE/NSF Review: February 17-19, 1999
7
150
Events
Events
Events
Resolution of 1/PTT
150
• Single µ’s with no
background
100
75
100
100
50
50
0
50
-0.2
0
0
0.2
25
-0.2
-1
-0.2
200
100
100
50
0.2
1/Ptrec-1/Ptgen (GeV )
Events
150
0
-1
1/Ptrec-1/Ptgen (GeV )
Events
Events
0
0.2
-1
1/Ptrec-1/Ptgen (GeV )
300
0
100
75
• Distributions are
Gaussian
50
0
-0.1
0
0
0.1
25
-0.1
-1
200
150
100
100
50
0
0.1
-1
1/Ptrec-1/Ptgen (GeV )
Events
Events
250
200
0
-0.1
1/Ptrec-1/Ptgen (GeV )
Events
300
0
0.1
-1
1/Ptrec-1/Ptgen (GeV )
400
0
• No significant tails
150
100
50
-0.1
0
0.1
-1
1/Ptrec-1/Ptgen (GeV )
0
-0.1
0
0.1
0
-0.1
-1
1/Ptrec-1/Ptgen (GeV )
US CMS DOE/NSF Review: February 17-19, 1999
0
0.1
-1
1/Ptrec-1/Ptgen (GeV )
8
σ( 1/Ptrec - 1/Ptgen )/( 1/Ptgen )
Expected PTT Resolution
from CSC Track-Finder
1
Pt = 10 GeV
0.9
Pt = 50 GeV
Pt = 100 GeV
0.8
ME1/3
0.7
ME1/2
ME1/1
MB1
• PT obtained from ∆ϕ
measured between
MB1-ME1 (0.9<η<1.2)
ME1-ME2 (1.2< η<2.4)
0.6
• Resolution ~30% at
low PT
0.5
0.4
0.3
0.2
0.1
MB1 / ME1 / ME2
0
0.8
1
1.2
1.4
1.6
1.8
2
US CMS DOE/NSF Review: February 17-19, 1999
2.2
• Expected to be
improved as TrackFinder design evolves
2.4
ηrec
9
σ( 1/Ptrec - 1/Ptgen )/( 1/Ptgen )
PTT Resolution with & without
Measurement in MB1 or ME1
1.4
ME2 - ME3
ME1/3 - ME2/2
ME1 - ME2
MB1 - ME1/3
Pt = 10 GeV
1.2
1
0.8
• PT Resolution ~70%
without MB1 in overlap
region, or without ME1
in endcap
• Cannot satisfy single µ
rate requirement
without station 1
0.6
0.4
0.2
0
0.8
1
1.2
1.4
1.6
1.8
2
US CMS DOE/NSF Review: February 17-19, 1999
2.2
2.4
ηrec
10
Efficiency in Overlap Region
η = 0.2
η = 0.4
η = 0.6
η = 0.8
η = 1.0
η = 1.2
η = 1.4
η = 1.6
η = 1.8
η = 2.0
• Barrel and endcap trigger systems share
information in overlap region
• Either system can identify muons in this region,
but sharp η cut will prevent duplication
US CMS DOE/NSF Review: February 17-19, 1999
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Overlap Region: No Sharing
η = 0.2
η = 0.4
η = 0.6
η = 0.8
η = 1.0
η = 1.2
η = 1.4
η = 1.6
η = 1.8
η = 2.0
CSC only
Efficiency
Efficiency
DT only
η
η
• CMSIM study performed by Vienna
• Poor efficiency around η=1 without sharing
US CMS DOE/NSF Review: February 17-19, 1999
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η = 0.2
η = 0.4
η = 0.6
η = 0.8
Efficiency
Overlap Region:
Barrel+ME1/3+ME2/2
η = 1.0
η = 1.2
η = 1.4
η = 1.6
η = 1.8
Extended DT
coverage
Efficiency
η = 2.0
CSC coverage without DT
η
• Require DT and CSC information in overlap region
for efficient coverage
• Will define a sharp η boundary to avoid duplication
US CMS DOE/NSF Review: February 17-19, 1999
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