CMS Tracker Detector Performance Results

Plots and Results

8TeV Data

Contact: Janos Karancsi, Janos.Karancsi@cernNOSPAMPLEASE.ch and Viktor Veszpremi, Viktor.Veszpremi@cernNOSPAMPLEASE.ch

Presenting for approval on Apr 12, 2013

Definition of efficiency: N_valid + N_missing_with_cluster / (N_valid + N_missing), for Rechits with no other Rechits within 5 mm. N_missing_with_cluster : Missing RecHits with a cluster within 500 um.

Event selection: \x{2265}1 vertex, where |z|<25 cm, |\x{03c1}|<2.0 cm, N_dof >4. track selection: General track seeded from the Pixels, valid hits always required on "other" layers in order to minimize bias from seeding. Track p_T>1.0 GeV, N_strip_hits >10, track consistent with vertex (cut on impact parameters d0, dz - layer dependent), track separation (RecHits separated by 5mm)

The innermost modules of Disk 1 were excluded.

Hit Finding Efficiency vs Layers and Disks - 2012

Average Layer/Disk Efficiencies: SEU candidates and DAQ errors are excluded.

lay.png
Average Hit Fining Efficiency vs layers and disks in 2012 Data

Dynamic Inefficiencies:

The data used in these plots only includes the highest intensity fills of 2012 (more than 1300 colliding bunches).

Instantaneous Luminosity Level 1 Trigger Rate
instlumi all.png
Efficiency vs Instantaneous Luminosity for all Layers and Disks
l1rate all.png
Efficiency vs Level 1 Trigger Rate for all Layers and Disks

2012 runs: The plots show the variations of efficiencies throughout 2012 runs (Note: the scale is not linear in time).

Barrel Pixel Forward Pixel
run bpix.png
Efficiency for each barrel layer vs 2012 runs (time scale is not linear)
run fpix.png
Efficiency for each forward disk vs 2012 runs (time scale is not linear)

Typical 2012 Fills:

Fill #2736 Fill #3239
instlumi 2736 all.png
Efficiency vs Instantaneous Luminosity in Fill #2736 (16 June 2012)
instlumi 3236 all.png
Efficiency vs Instantaneous Luminosity in Fill #3236 (28 October 2012)

All High Voltage Bias Scans - Up to 2013

Layer 1 Scans:

Efficiency Normalized Charge MPV
hv l1 eff.png
Efficiency vs Bias Voltage for all Layer 1 Scans up to 2013. Points were fitted with a turnon curve.
hv l1 mpv.png
MPV of Normalized Charge vs Bias Voltage for all Layer 1 Scans up to 2013. Points were fitted with a modified turnon curve.

Layer 2 Scans:

Efficiency Normalized Charge MPV
hv l2 eff.png
Efficiency vs Bias Voltage for all Layer 2 Scans up to 2013. Points were fitted with a turnon curve.
hv l2 mpv.png
MPV of Normalized Charge vs Bias Voltage for all Layer 2Scans up to 2013. Points were fitted with a modified turnon curve.

Layer 3 Scans:

Efficiency Normalized Charge MPV
hv l3 eff.png
Efficiency vs Bias Voltage for all Layer 3 Scans up to 2013. Points were fitted with a turnon curve.
hv l3 mpv.png
MPV of Normalized Charge vs Bias Voltage for all Layer 3 Scans up to 2013. Points were fitted with a modified turnon curve.

Full Disk 1 Scans:

Efficiency Normalized Charge MPV
hv d1full eff.png
Efficiency vs Bias Voltage for all Full Disk 1 Scans up to 2013. Points were fitted with a turnon curve.
hv d1full mpv.png
MPV of Normalized Charge vs Bias Voltage for all Full Disk 1 Scans up to 2013. Points were fitted with a modified turnon curve.

Full Disk 2 Scans:

Efficiency Normalized Charge MPV
hv d2full eff.png
Efficiency vs Bias Voltage for all Full Disk 2 Scans up to 2013. Points were fitted with a turnon curve.
hv d2full mpv.png
MPV of Normalized Charge vs Bias Voltage for all Full Disk 2 Scans up to 2013. Points were fitted with a modified turnon curve.

Summary plots - All High Voltage Bias Scans:

The Following plots were derived from the above plots: The efficiency vs Bias voltage plots were fitted with turnon function (shown above on the left plots). The Bias voltage, where the efficiency is 1% below maximum were taken from the fitted functions. Similarly, the MPV vs Bias Voltage plots were also fitted with modified turnon curves. The MPV that corresponds to the "99% Efficiency" Voltage were taken using the fitted function (shown above on the right plots).

Voltage at 99% Hit Efficiency Norm Charge MPV at the 99% Hit Efficiency
vturnon totlumi.png
Bias Voltage at 99% Hit Efficiency vs Total Integrated Luminosity for all Bias Scans up to 2013
mpv vturnon totlumi.png
Normalized Charge MPV at 99% Hit Efficiency vs Total Integrated Luminosity for all Bias Scans up to 2013

Contact: Silvia Taroni Silvia.Taroni@cernNOSPAMPLEASE.ch

Presenting for approval on Apr 12, 2013

Analized run 201278, taken 21st August 2012, 8 TeV p - p collisions, Inst Lum from 6.3 x 10 ^{33} to 2 x 10^{33) cms ^{-2}s^{-1}.

To study possible dependencies of the cluster size and charge on the instantaneous luminosity, the run has been divided into 20 Instantaneous luminosity intervals. For each interval, a Monte Carlo (MC) simulation has been performed using the pile up distributions from data to simulate the pile up in MC. This procedure allows a more precise data - MC comparison, since the two samples have the same pile up.

Few basic selections have been applied for selecting events. Vertex requests: number of Vertices > 0, ndof < 5, z < 24 cm, position rho > 2. Track requests: track pt > 0.6 GeV

Data are from Minimum Bias primary dataset requiring HLT_ZeroBias trigger.

Used CMSSW releases: CMSSW_5_3_2_patch4 for MC and CMSSW_5_3_3_patch1 for data

Cluster Size

The cluster size of each on-track cluster has been considered. We have analysed the global cluster size, the size along x and along y direction. Considering clusters having the global/x/y size from 0 to 20, we can observe only minor differences in the cluster size distributions of data and MC. The plots are normalized to the area.

* ClusterSize:
c_hclustsizevsLayerData_2.png c_hclustsizexvsLayerData_2.png c_hclustsizeyvsLayerData_2.png

The average cluster size (considering cluster smaller than 20 pixel in total or along x or y) has been studied as a function of the instantaneous luminosity. There are differences in the three layers but no dependence on the instantaneous luminosity has been observed as in MC.

* average cluster size vs inst lim:
hclustsizevsLS_Mean_allLayers.png hclustsizeXvsLS_Mean_allLayers.png hclustsizeYvsLS_Mean_allLayers.png

Cluster Charge

The collected cluster charge has been also investigated. Considering on-track clusters, the charge has been studied separately for the three layers. For each instantaneous luminosity interval, the cluster charge in each layer has been fitted using a landau distribution convoluted with a gaussian. As an example, in the below plot we show the histogram and the fit for layer 2 for inst lumi ~5.6 x 10^{33} cm{-2}s{-1}. The only difference we see is the peak position: the peak from data is shifted wrt the simulated one.

* Cluster charge fit layer 2:
clusterChargeFitLayer2.png

Plotting the MPV as a function of the instantaneous luminosity we have observed 2 effects. The difference between layers, expected from the different dose absorbed by the three layers, and a dependence on luminosity: the peak moves to higher values with the decrease of the luminosity. This can be explained as dependent on the readout electronics and not as a real increase in charge collection efficiency: the higher occupancy produces an increase of the readout chip temperature that influence the charge value in output. This effects is not simulated in MC.

* cluster charge MPV vs Inst Lum:
chargeChangeLayervsLS.png

Contact: Armin Burgmeier Armin.Burgmeier@cernNOSPAMPLEASE.ch

Presenting for approval on Apr 12, 2013

The pixel resolution of the pixels in PXB2 has been measured. Tracks with pT > 12 GeV having hits in all three layers of the pixel barrel detector have been selected. The tracks are re-fit without the hit in the 2nd layer. Then, the residual difference between the hit position and the interpolated track is plotted. A student-t function is fit to the distribution. Assuming the resolution is the same in all three layers the width of the function fit divided by sqrt(3/2) gives the intrinsic pixel resolution. This takes into account that the hit positions in layers 1 and 3 are smeared as well.

The following datasets and conditions were used to create these plots:

  • Datasets: * /Jet/Run2012A-22Jan2013-v1/RECO * /JetHT/Run2012B-22Jan2013-v1/RECO * /JetHT/Run2012C-PromptReco-v1/RECO * /JetHT/Run2012C-PromptReco-v2/RECO * /JetHT/Run2012D-PromptReco-v1/RECO
  • RecHits are being reconstructed with the template builder ("WithAngleAndTemplate")
  • Global Tag: GR_R_53_V18::All * Override template tag: SiPixelTemplateDBObject_38T_v6_offline * This is equivalent to the conditions used for the Winter13 Re-Reco

Example Triplet Residual distribution

An example triplet residual distribution from run 207487

207487_h420.png

Intrinsic Pixel Resolution as a function of time

The intrinsic pixel resolution is shown as a function of integrated luminosity. There is one data point for about every 500/pb of data taken. Each data point corresponds to one collision run.

PXB2_residuals.png

Contact: Jelena Luetic jelena.luetic@cern.ch

Presenting for approval on Apr 12, 2013

Pixel cluster parameters, cluster size and cluster charge, were determined as a function of integrated luminosity. Data points correspond to a measurement for a certified longer run taken approximately every 0.5/fb. Selected events are required to have clusters on tracks with track pt > 1GeV.

Cluster Charge

Cluster charge distribution was determined for each layer in pixel barrel and fitted to Landau distribution convoluted with Gaussian. Charge most probable value was extracted from the fit.

* Example of fit for each layer

l1.pngl2.pngl3.png

* Cluster charge vs. integrated luminosity

Changes in cluster charge MPV at 6.5/fb and 15/fb correspond to threshold readjustments during LHC technical stops and changes at 8/fb and 18/fb correspond to implementation of new gain calibration.

MPVwm.png

Cluster Size

Cluster size as a function of integrated luminosity was determined as a mean of the distribution for global cluster size, as well as for cluster sizes in local x and y directions. Jumps in cluster size at 6.5/fb and 15/fb correspond to threshold readjustments during LHC technical stops.

CLSize.pngCLsizex.pngCLsizey.png

Contact: Jelena Luetic jelena.luetic@cern.ch

Presenting for approval on Apr 12, 2013

Lorentz angle as a function of integrated luminosity was determined using grazing angle method for 2012 data. Each data point represents Lorentz angle for a longer run taken approximately every 0.25/fb.

Basic selection requirements include high purity muon track, cluster size in y>4, track pt>3 GeV, cluster charge < 120000 e, hit residuals < 50 micrometers and chi2/ndof<2. Edge pixels were excluded as well.

Lorentz angle vs Integrated Luminosity

LA2012.png

Lorentz angle for special runs

At the end of the run period, in 2012, data was taken with bias voltages different from nominal bias voltage value 150 V. Approximately 25/pb was taken with bias voltages 140V and 160V and some data (only few minutes of data taking) was taken with bias voltage of 300V. Lorentz angle was determined for each of these special runs with grazing angle method and plotted together with Lorentz angle in 2012 (luminosity not to scale).

LA2012_specRuns.png

Contact: Danek Kotlinski danek.kotlinski@psiNOSPAMPLEASE.ch

Presenting for approval on Apr 12, 2013

The average pixel thresholds measured with charge injection, using the "S-Curve" method. The thresholds are averaged over pixel barrel layers 1, 2 and 3 and over forward pixels. The steps at 6.0, 12.5 and 21 fb-1 correspond to readjustment of the thresholds, which have been performed at the beginning of 2012 and during two LHC technical stops during 2012 running period.

Plot of pixel thresholds during 2011 and 2012

The average pixel thresholds in units of 1000 electrons (1 ke) for barrel layers 1 (black) , 2 (red) and 3 (blue), and for the forward pixels (green) as a function of delivered integrated luminosity in 2011 and 2012.

plot_thr_vs_lumi_11_12.png

Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng 207487_h420.png r1 manage 25.4 K 2013-04-11 - 12:10 ArminBurgmeier Example residual distribution
PNGpng CLSize.png r1 manage 19.1 K 2013-04-11 - 17:37 JelenaLuetic Cluster size vs integrated luminosity
PNGpng CLsizex.png r1 manage 25.3 K 2013-04-11 - 17:37 JelenaLuetic Cluster size vs integrated luminosity
PNGpng CLsizey.png r1 manage 22.6 K 2013-04-11 - 17:37 JelenaLuetic Cluster size vs integrated luminosity
PNGpng LA2012.png r1 manage 21.4 K 2013-04-11 - 18:28 JelenaLuetic Lorentz Angle vs integrated luminosity
PNGpng LA2012_specRuns.png r1 manage 30.1 K 2013-04-11 - 18:02 JelenaLuetic Lorentz Angle vs integrated luminosity with special runs
PNGpng MPVwm.png r1 manage 28.1 K 2013-04-11 - 17:04 JelenaLuetic Pixel charge MPV vs Integrated luminosity
PNGpng PXB2_residuals.png r1 manage 20.3 K 2013-04-11 - 12:10 ArminBurgmeier PXB2 pixel resolution as a function of time
PNGpng c_hclustsizevsLayerData_2.png r1 manage 15.3 K 2013-04-11 - 12:19 SilviaTaroni  
PNGpng c_hclustsizexvsLayerData_2.png r1 manage 15.1 K 2013-04-11 - 12:19 SilviaTaroni  
PNGpng c_hclustsizeyvsLayerData_2.png r1 manage 15.1 K 2013-04-11 - 12:19 SilviaTaroni  
PNGpng chargeChangeLayervsLS.png r1 manage 18.1 K 2013-04-11 - 09:37 SilviaTaroni cluster charge MPV vs Inst Lum
PNGpng clusterChargeFitLayer2.png r1 manage 17.2 K 2013-04-11 - 12:19 SilviaTaroni  
PNGpng hclustsizeXvsLS_Mean_allLayers.png r1 manage 19.0 K 2013-04-11 - 09:33 SilviaTaroni Average cluster size along x direction vs Inst Lum
PNGpng hclustsizeYvsLS_Mean_allLayers.png r1 manage 18.4 K 2013-04-11 - 09:34 SilviaTaroni average cluster size along y direction vs Inst Lum
PNGpng hclustsizevsLS_Mean_allLayers.png r1 manage 19.3 K 2013-04-11 - 09:35 SilviaTaroni average cluster size vs inst lim
PNGpng hv_d1full_eff.png r1 manage 21.0 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_d1full_mpv.png r1 manage 24.2 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_d2full_eff.png r1 manage 21.8 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_d2full_mpv.png r1 manage 24.9 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l1_eff.png r1 manage 35.8 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l1_mpv.png r1 manage 39.9 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l2_eff.png r1 manage 25.6 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l2_mpv.png r1 manage 28.0 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l3_eff.png r1 manage 29.6 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng hv_l3_mpv.png r1 manage 31.9 K 2013-04-11 - 00:01 JanosKarancsi  
PNGpng instlumi_2736_all.png r1 manage 27.1 K 2013-04-11 - 00:02 JanosKarancsi  
PNGpng instlumi_3236_all.png r1 manage 26.4 K 2013-04-11 - 00:02 JanosKarancsi  
PNGpng instlumi_all.png r2 r1 manage 23.8 K 2013-04-11 - 01:09 JanosKarancsi  
PNGpng l1.png r1 manage 15.6 K 2013-04-11 - 17:35 JelenaLuetic Landau fit example
PNGpng l1rate_all.png r1 manage 23.6 K 2013-04-11 - 00:02 JanosKarancsi  
PNGpng l2.png r1 manage 15.1 K 2013-04-11 - 17:35 JelenaLuetic Landau fit example
PNGpng l3.png r1 manage 16.6 K 2013-04-11 - 17:35 JelenaLuetic Landau fit example
PNGpng lay.png r1 manage 12.6 K 2013-04-11 - 00:02 JanosKarancsi  
PNGpng mpv_vturnon_totlumi.png r1 manage 21.2 K 2013-04-11 - 01:26 JanosKarancsi  
PNGpng plot_thr_vs_lumi_11_12.png r1 manage 21.4 K 2013-04-11 - 17:31 DanekKotlinski Pixel threholds for 2011 and 2012
PNGpng run_bpix.png r2 r1 manage 27.9 K 2013-04-11 - 01:23 JanosKarancsi  
PNGpng run_fpix.png r2 r1 manage 27.4 K 2013-04-11 - 01:23 JanosKarancsi  
PNGpng vturnon_totlumi.png r1 manage 19.4 K 2013-04-11 - 01:26 JanosKarancsi  
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