Energy loss study of TeV ’slacaprar/talks/PRSMU_20040608.pdf · 2004-06-08 · CMS PRS- , CMS...
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CMS PRS-μ, CMS week CERN, Tuesday 8 June 2003 Energy loss study of TeV μ’s Stefano Lacaprara [email protected] INFN and Padova University Stefano Lacaprara – PRS-μ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV μ’s – p.1/21
Transcript of Energy loss study of TeV ’slacaprar/talks/PRSMU_20040608.pdf · 2004-06-08 · CMS PRS- , CMS...
CMS
PRS-µ, CMS week
CERN, Tuesday 8 June 2003
Energy loss study of TeV µ’s
Stefano [email protected]
INFN and Padova University
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.1/21
CMS
MotivationIncreasing interest in high pt muons,
Eg. Z ′ search,
Large room for improvements and
optimization in actual muon reconstruction,
Major concern is energy loss (brem) along
muon trajectory,
How to recognize it?
How to improve muon fit?
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.2/21
CMS ApproachesSo far a “top-bottom” approach
Look at high level reconstruction quantities (such asdi-µ invariant mass) and see the effect of differentreconstruction algorithms on it: eg Truncated MuonReconstructionEffect on 1/pt resolution and pullsLook at Kalman filter output (χ2)Found possible algorithm optimization
Try “Bottom-top” approachLook at MC to see how high pt muons behaves inCMSLook at energy deposit along muon trajectoryLook at hits multiplicity on muon chambersLook at pt, η reconstructed in Tracker and Muonsystems alone
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.3/21
CMS
ToolsSample single µ, mixed charge, pt = 1 TeV , |η| < 2.5,CMSIM 133Maybe not the best sample: at high η the pµ
t is notrelevant for CMS (e.g. p ≈ 3.5 TeV ). Will try p = 1 TeVStandard geometry (with wrong Al and DT gas densityin DT system)Reconstruction with ORCA 813 (plus various bugs fix, tobe released in 820 soon)Check µ energy loss in Tracker (from IP to outermost Tklayer), Calo’s (outermost Tk – innermost Muon station),Muon (innermost – outside)Compare µ energy loss with SimHits multiplicityDitto for RecHits (layer hits)η independent study
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.4/21
CMS
µ energy loss (fraction)hEnLossTotFrac
Entries 99044
Mean 0.03039
RMS 0.06768
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
10
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hEnLossTotFrac
Entries 99044
Mean 0.03039
RMS 0.06768
tot
tk
calo
mu
Total muon energy loss (fraction) hEnLossMuFrac
Entries 99044
Mean 0.01336
RMS 0.04578
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
1
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510
hEnLossMuFrac
Entries 99044
Mean 0.01336
RMS 0.04578
mu
sta 1->2
sta 2->3
sta 3->4
Muon muon energy loss (fraction)
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CMS
µ energy loss calo vs SimHit mult.
# SimHits station 10 20 40 60 80 100 120 140 160 180 200
frac
µ loss
E
0
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vs. # SHs st. 1µEn. loss
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.6/21
CMS
µ energy loss calo vs RecHit mult.
# RecHits station 10 20 40 60 80 100 120 140 160 180 200
frac
µ loss
E
0
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vs. # RHs st. 1µEn. loss
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CMS
µ energy loss Muon vs SimHit mult.
# SHs st. 2
0 50 100 150 200
en.
loss
µFr
ac
0
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st. 1->2
# SHs st. 3
0 50 100 150 2000
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st. 2->3
# SHs st. 4
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st. 3->4
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.8/21
CMS
µ energy loss Muon vs RecHit mult.
# RHs st. 2
0 50 100 150 200
en.
loss
µFr
ac
0
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st. 1->2
# RHs st. 3
0 50 100 150 2000
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st. 2->3
# RHs st. 4
0 50 100 150 2000
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st. 3->4
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.9/21
CMS
P µt Tk-Muon vs Calo En. loss
(pt outermost Tk st. - pt innermost Mu st.)/Gen. pt
calo (frac)µlossE
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
)/Gen
first
-Mu
last
(Tk
µPt
-10
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Pt Tk- Pt Muon vs En. loss calo
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CMS
χ2 Muon Fit vs Calo En. loss
calo (frac)µlossE
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
fit
µ^2
χ
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^2 Muon Fit vs En. loss caloχ
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.11/21
CMS
ηµ Tk-Muon vs Calo En. loss(η at outermost Tk station - η innermost Muon station )
calo (frac)µlossE
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
)/Gen
first
-Mu
last
(Tk
µEt
a
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Eta Tk- Eta Muon vs En. loss calo
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.12/21
CMS
Conclusion and futureVery preliminary study,Preliminary conclusion: hits multiplicity is not correlatedwith energy loss! Cannot use Muon station ascalorimeter!Not correct to rely on hit multiplicity to stop fit of muontracjectory,Need to use also station with very high multiplicity in thefitFirst test (not shown here) to “clusterize hits” incrowded chambers (DT), without pattern recongitionlooks not too bad,Naïve test of pt, ∆η, chi2 Tk vs Mu not very promisingMust repeat with OSCAR (also for cross check),More appropriate sample (p = 1 TeV ?)Must check energy measured by calo’s...
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.13/21
CMS Backup
Backup slides
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.14/21
CMS
∆Pt/Pt µ Muon only
-10 -8 -6 -4 -2 0 2 4 6 8 100
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µ p_t/p_t ∆
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CMS
∆Pt/Pt µ Tk only
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µ p_t/p_t ∆
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∆Pt/Pt µ Tk+Mu
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CMS
µ Charge assignment Mu only
-1.5 -1 -0.5 0 0.5 1 1.5
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µCharge ass.
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CMS
µ Charge assignment Tk only
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µCharge ass.
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CMS
µ Charge assignment Tk+Mu
-1.5 -1 -0.5 0 0.5 1 1.5
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µCharge ass.
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.20/21
CMS
µ Charge assignment Tk+Mu Vs EnLoss Calo
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-1.5
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En. loss (frac) CaloµCharge ass.
Stefano Lacaprara – PRS-µ, CMS week, CERN, Tuesday 8 June 2003 – Energy loss study of TeV µ’s – p.21/21
