Calibration of DT-MTCC data S.Bolognesi and G.Cerminara for the Torino group (N.Amapane, R.Bellan, C.Mariotti, G.Mila) DT Cosmic Analysis - CERN 26/09/2006

Outlook RUN 669 (local, B off), 2602 (global B=3.8 T) only events triggered by DTs vdrift calibration (first time on MTCC!!) vdrift = Lsemicell / tmeantime reconstruction efficiency segment quality hit resolution vdrift for B on (3.8 T) versus B off ttrig calibration: ttrig = tflex – k×s(ttrig) is k factor stable for different SL? ttrig and s(ttrig) for B on (3.8 T) S. Bolognesi and G. Cerminara (TORINO) 1 DT Cosmic Analysis - CERN 26/09/2006

Noise and ttrig calibr. Map of noisy channels using the standard test: look at occupancy before the time boxes (DQM/DTMonitorClient) noisy channels not used in ttrig and vdrift calibration Reading t0 from map and calibration of tTrig from fit of TB rising edge: tdrift = tmeasured – t0 – tTrig correction for propagation along the wire off because the effect is compensated by the BX assignment (see Mary Cruz presentation @ DT Meeting 08/29/06) (CalibMuon/DTCalibration) S. Bolognesi and G. Cerminara (TORINO) 2 DT Cosmic Analysis - CERN 26/09/2006

vdrift calibration CalibMuon/DTCalibration package now includes also code (written by M. Giunta) to calibrate vdrift for each SL meantimer calculation: different formulas for different track pattern (see M.Giunta presentation @ CMSWeek 08/06/04) meantimer histos fitted with an automatic algorithm drift velocity and hit resolution written in DB for each SL a new DTRecHit reconstruction algo which read vdrift from DB released RecoLocalMuon/DTRecHit/DTLinearDriftFromDBAlgo S. Bolognesi and G. Cerminara (TORINO) 3 DT Cosmic Analysis - CERN 26/09/2006

Residuals move to 0 the mean of residual on the distance from wire: | recHit position | - | segm. position | Distribution of the means for each SL before calibration after calibration Distribution of the sigmas for each SL incertezza sui cosmici mean 480mm Because of the BX assignment we get big sigma of residuals for cosmic data: mean 470 mm sigma ~ √2002 + 4002 mm ~ 450 mm cell resolution ~ 200 mm BX assignement (25 ns/√12)×54 mm/ns ~ 400 mm S. Bolognesi and G. Cerminara (TORINO) 4

Efficiency and c2 increase the efficiency of the segment reconstruction: improve the chi2 of the segments: c2 reduced mean on all the chambers Impact angle (W1 St2 Sec10) before calibration 3.0 after calibration 2.5 c2 reduced (W1 St1 Sec10) Summing on all the chambers we get 4D segments / event before calibration 1.7 after calibration 1.8 S. Bolognesi and G. Cerminara (TORINO) 5 DT Cosmic Analysis - CERN 26/09/2006

Number of hits number of hits for each segment increases # of hits for segment (W1 St2 Sec10) # of hits for segment (W1 St4 Sec14) before calibration 8 hits after calibration 12 hits After the calibration: better knowledge of vdrift for each SL good estimation of the hit resolution for each SL S. Bolognesi and G. Cerminara (TORINO) 6 DT Cosmic Analysis - CERN 26/09/2006

vdrift with B on ~2% B off (local run) B = 3.8 T (global run) MB1 MB2 MB3 MB4 W2 W1 W2 W1 W2 W1 W2 W1 W1 W2 14 14 10 10 11 10 10 11 10 10 11 10 10 11 B off (local run) B = 3.8 T (global run) ~2% vdrift for each SL MB1 MB2 MB3 MB4 W1 W2 W1 W2 W1 W2 W1 W2 W1 W2 10 10 11 10 10 11 10 10 11 10 10 11 14 14 MB1 W2 effetto maggiore come atteso vdrift(Boff) - vdrift(Bon) vdrift(Boff) for each SL SL theta SL phi 7 CERN 26/09/2006

Hit resolution hit resolution distribution for each SL hit resolution = vdrift × smeantimer hit resolution distribution for each SL MB1 MB2 MB3 MB4 mean 560mm mean 600mm W1 W2 W1 W2 W1 W2 W1 W2 W1 W2 10 10 11 10 10 11 10 10 11 10 10 11 14 14 deviation from linearity B off (local run) CMS NOTE 2005/018 B = 3.8 T (global run) With B on the resolution become worse because of deviations from linearity S. Bolognesi and G. Cerminara (TORINO) 8

ttrig calibration: k factor k factor for each superlayer choosen by minimizing the residuals (after vdrift calibration by SL) ttrig = tflex – k×s(ttrig) see S.B. presentation @ Muon Software Session 02/09/06 Distribution of k factor Distribution of sttrig Distribution of k × sttrig mean 7.3 ns mean -7.3 ns mean -0.99 +/- 0.01 RMS 0.88 ns std. dev. -0.03 +/- 0.01 RMS 0.94 ns RMS 0.093 RMS (k) × <sttrig> < RMS (k × sttrig) i.e. the fluctuations of k factor are smaller than the k*sttrig fluctuations The use of k factor is convenient: local fluctuations absorbed by sttrig and vdrift k factor quite constant on all the chambers and SLs S. Bolognesi and G. Cerminara (TORINO) 9 DT Cosmic Analysis - CERN 26/09/2006

ttrig with B on tTrig B off (local run) B = 3.8 T (global run) MB1 MB2 MB3 MB4 W1 W2 W1 W2 W1 W2 W1 W2 W1 W2 B off (local run) B = 3.8 T (global run) 10 10 11 10 10 11 10 10 11 10 10 11 14 14 s(tTrig) MB1 MB2 MB3 MB4 TOF effect (10 ns) W1 W2 W1 W2 W1 W2 W1 W2 W1 W2 10 10 11 10 10 11 10 10 11 10 10 11 14 14 sttrig distribution for each SL mean -7.1 ns mean -8.1 ns s(tTrig) increases of about 1 ns with B on because of the field lines distortion S. Bolognesi and G. Cerminara (TORINO) 10

Conclusions Code to calibrate vdrift for each SL released Preliminary test of vdrift calibration on cosmic data: vdrift better knowledge of for each SLs hit resolution enhance of the reconstruction efficiency improvement of the segment quality B on VS B off comparison for vdrift and hit resolution: right order of magnitude and reasonable behaviour but further studies still to be done check of the k factor recipe after the vdrift calibration check of the ttrig calibration with B on VS B off S. Bolognesi and G. Cerminara (TORINO) 11 DT Cosmic Analysis - CERN 26/09/2006