dt calibration status a. vilela pereira for the dt calibration team (università degli studi di...
TRANSCRIPT
DT calibration status
A. Vilela Pereira for the DT calibration team(Università degli Studi di Torino & INFN
Torino)Muon Barrel Workshop – July 7 2010
Outline
07/07/2010
DT Calibration - Muon Barrel Workshop2
• Highlights from CMS Week
• Collision events selection
• Computation of tTrig DB from time boxes
• Residuals and tTrig corrections
Status from CMS Week
07/07/2010
DT Calibration - Muon Barrel Workshop3
Possible to start computing tTrig with SL granularity
MinimimBias GOODCOLL Skim
Mu DtCalib ALCARECODedicated DT calibration ALCARECO data set however suffers from large background from cosmics
Outline
07/07/2010
DT Calibration - Muon Barrel Workshop4
• Highlights from CMS Week
• Collision events selection
• Effect on residuals and segment t0 distributions
• Computation of tTrig DB from time boxes
• Residuals and tTrig corrections
Datasets and collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop5
/MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO
/Commissioning/Run2010A-MuonDPG_skim-May27thSkim_v2/RAW-RECO
/Mu/Run2010A-DtCalib-*/ALCARECO
DT activity + muon selection, BPTX + cleaning of scraping events and beam backgrounds
On RECO datasets required primary vertex
On ALCARECO datasets required BSC coincidence (but no primary vertex, whose collection is not in the event content)
Residuals – Collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop6
MB1 MB2
MB3 MB4
Wheel 0 Sector 4 SL1
N.B. Residuals computed using current tTrig table in Global tag
Sub-sample of events passing collision criteria
Residuals – Collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop7
MB1 MB2
MB3 MB4
Wheel 0 Sector 7 SL1
Vetical sectors less dominated by cosmics
Segment t0 – Collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop8
MB1 MB2
MB3MB4
Wheel 0 Sector 4 – RPhi segment
Segment t0 – Collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop9
MB1 MB2
MB3 MB4
Wheel 0 Sector 7 – RPhi segment
Outline
07/07/2010
DT Calibration - Muon Barrel Workshop10
• Highlights from CMS Week
• Collision events selection
• Computation of tTrig DB from time boxes
• Residuals and tTrig corrections
Time boxes
07/07/2010
DT Calibration - Muon Barrel Workshop11
/MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO
MB1 MB2 MB3
MB4Statistics reduced as one goes further from IP
Somewhat increased noise in Minimum bias data set
Reminder of tTrig computation
07/07/2010
DT Calibration - Muon Barrel Workshop12
i. Inter-channel calibration (t0): per wire relative times from test pulses
ii. ttrig: Time pedestal from fit to rising-edge of time box: • Gives tmean & (tmean)• Additional k-Factor
needed to tune the final time pedestal:
Note: k-Factor also in tTrig DB (per SL):
ttrig = tmean + k x
tTrig DB
tmean (tmean) k-Factor
tTrig workflow
07/07/2010
DT Calibration - Muon Barrel Workshop13
DTTTrigCorrection
DTTTrigResidual
Correction…
tmean, (tmean)
ttrig = tmean + k x
tmean, (tmean),k-Factor
tTrig DB
tmean (tmean) k-Factor
ttrig pedestals from fit to rising-edge of time box, with super-layer granularity
Uncertainty in fitting of the time box requires a further correction to remove (reduce) bias in residuals
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop14
SL1
SL3
SL2
/MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO
tTri
g (
ns)
N.B. tTrig from current DB ~322 ns
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop15
SL1
SL3
SL2
/Mu/Run2010A-DtCalib-May27thReReco_v2/ALCARECO
SL1
tTri
g (
ns)
tTri
g s
igm
a (n
s)
tTri
g (
ns)
tTri
g (
ns)
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop16
SL1
SL3
SL2
tTri
g (
ns)
Wh0
tTrig values consistent when running on different datasets and different collision event selection
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop17
SL1
SL3
SL2
tTri
g (
ns)
Wh2
Some discrepancy in Wheels +/- 2 in MB1, as shown before during CMS Week
Effect could be related to different vDrift in this chamber (constant in DB)
Residuals from calculated tTrig db
07/07/2010
DT Calibration - Muon Barrel Workshop18
Wh0
Residuals within ~100 μm
Remaining bias expected to be reduced by using effective vDrift procedure (see past presentations)
Effect of residual correction
07/07/2010
DT Calibration - Muon Barrel Workshop19
Wh0ttrig = tmean + k x
Summary & Next steps
07/07/2010
DT Calibration - Muon Barrel Workshop20
• First results from tTrig from collisions. Consistent results from previously estimated values from cosmics.
• Collision selection studied should finalize criteria and include either in the DT ALCARECO production or leave it in the calibration workflow (possibly updating ALCARECO event content).
• Automatic tTrig calibration procedure has been updated and used regularly.
• tTrig DB could be loaded for tests.
• Results for more recent runs to be produced soon.
Backup
07/07/2010
DT Calibration - Muon Barrel Workshop21
Segment t0 – Collision selection
07/07/2010
DT Calibration - Muon Barrel Workshop22
MB1 MB2
MB3
Wheel 0 Sector 4 – RZ segment
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop23
SL1
SL3
SL2
tTri
g (
ns)
Wh-2
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop24
SL1
SL3
SL2
tTri
g (
ns)
Wh-1
tTrig from calibration workflow
07/07/2010
DT Calibration - Muon Barrel Workshop25
SL1
SL3
SL2
tTri
g (
ns)
Wh1
Residuals from new tTrig db
07/07/2010
DT Calibration - Muon Barrel Workshop26
Wh-2 Wh-1
Residuals from new tTrig db
07/07/2010
DT Calibration - Muon Barrel Workshop27
Wh1 Wh2
tTrig corrections
07/07/2010
DT Calibration - Muon Barrel Workshop28
DTTTrigCorrection
DTTTrigMatchRPhi
DTTTrigResidual
CorrectionDTTTrigT0SegCorrection
…
tmean, (tmean)
ttrig = tmean + k x
tmean, (tmean),k-Factor
• Implemented series of “corrections” on top of original DB:
i. Match time pedestal values for two R- SL’s
ii. Automatic tuning of k-Factor
iii. Fill missing values, etc. tTrig DB
tmean (tmean) k-Factor
tTrig calibration
07/07/2010
DT Calibration - Muon Barrel Workshop29
tTrig correctio
n I
tTrig correctio
n II
vDrift
DTTTrigMatchRPhi
DTTTrigResidual
CorrectionDTTTrigT0SegCorrection
…
tmean, (tmean)
tTrig DB
tmean, (tmean),k-Factor