Public Inner Detector Plots for Collision Data

Introduction

Approved plots that can be shown by ATLAS speakers at conferences and similar events.
Please do not add figures on your own. Contact the responsible project leader in case of questions and/or suggestions.

Links to related information

• Public event displays from first collisions
• Tracking Performance results (Note - the first K0s plots have been moved to the tracking performance page.)
• BCM results from collision data
• Pixel results from collision data
• SCT results from collision data
• TRT results from collision data
• Beamspot results from collision data

Results from previous years

• 2009

Alignment Performance with 2010 7 TeV Collisions data

The validation plots below show the performance of the alignment which was used for the May 2010 reprocessing. This alignment was derived using the Global X2 algorithm using the 2009 900 GeV collisions dataset, and corresponds to the following alignment tags:

• IndetTrkErrorScaling-007-00
• InDetAlign_Collision_2009_08
• TRTAlign_Collision_2009_04

Unbiased residual distribution in x, integrated over all hits-on-tracks in the pixel barrel for the MC perfect alignment (red) and the current alignment with sqrt(s)=7 TeV collision data (run 153565) taken in 2010 (blue). The MC distributions are normalised to the number of entries in the data distributions. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV and ≥ 6 silicon hits. The FWHM/2.35 of the distributions are quoted.	eps version of the figure
Unbiased residual distribution in x, integrated over all hits-on-tracks in the pixel endcaps (both endcaps A and C) for the MC perfect alignment (red) and the current alignment with sqrt(s)=7 TeV collision data (run 153565) taken in 2010 (blue). The MC distributions are normalised to the number of entries in the data distributions. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV and ≥ 6 silicon hits. The FWHM/2.35 of the distributions are quoted.	eps version of the figure
Unbiased residual distribution in x, integrated over all hits-on-tracks in the SCT barrel for the MC perfect alignment (red) and the current alignment with sqrt(s)=7 TeV collision data (run 153565) taken in 2010 (blue). The MC distributions are normalised to the number of entries in the data distributions. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV and ≥ 6 silicon hits. The FWHM/2.35 of the distributions are quoted.	eps version of the figure
Unbiased residual distribution in x, integrated over all hits-on-tracks in the SCT endcaps (both endcaps A and C) for the MC perfect alignment (red) and the current alignment with sqrt(s)=7 TeV collision data (run 153565) taken in 2010 (blue). The MC distributions are normalised to the number of entries in the data distributions. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV and ≥ 6 silicon hits. The FWHM/2.35 of the distributions are quoted.	eps version of the figure
The TRT unbiased residuals, as obtained from 7 TeV collision data (run 153565) and Monte Carlo, separately for the barrel and end-caps. The Monte Carlo distributions are normalized to the number of entries in the data. Tracks are required to have: pT > 2 GeV and >= 6 silicon hits. The Full-Width-Half-Maximum reported in the plots (FWHM/2.35) is comparable to the sigma of a single Gaussian fit. A single Gaussian fit (iterated until the range corresponds to +/- 1.5*sigma) gives 144 microns (144 microns) and 165 microns (136 microns) for barrel and end-cap data (MC), respectively. For these low-momentum tracks, the width of the residual distribution is larger than the intrinsic accuracy per hit expected from the drift-time measurement because of the contribution from multiple scattering to the track parameter errors. The measured resolution in the end-caps is worse than in the barrel and than that expected from the Monte Carlo. Unlike the barrel, the TRT end-cap geometry did not allow for detailed studies with cosmic rays, further commissioning of the TRT end-caps is required to achieve performance similar to that of the barrel.	eps version of the figure eps version of the figure

Alignment Performance with 2010 7 TeV Collisions data and October 2010 alignment (Autumn reprocessing constants)

The validation plots below show the performance of the alignment which was used for the Autumn 2010 reprocessing. This alignment was derived using the Global X2 algorithm using the 2010 7 TeV GeV collisions dataset, and corresponds to the following alignment tags

• Silicon constants: InDetAlign_Collision_7T_2010_07
• TRT alignment constants: TRTAlign_Collision_7T_2010_07
• TRT L3 alignment constants: TRTCalibDX_L3BarrelEndcap_01
• Error scaling: TrkErrorScaling_7T_2010_03
• All this tags are collected in: COMCOND-REPPxx-007-05 family

Distribution of the local x unbiased residuals of the pixel barrel modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution). The local x coordinate of the pixels is along the most precise pixel direction.	eps version of the figure
Distribution of the local y unbiased residuals of the pixel barrel modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution). The local y coordinate of the pixels is along the broad pixel direction.	eps version of the figure
Distribution of the local x unbiased residuals of the pixel end-cap modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution).The local x coordinate of the pixels is along the most precise pixel direction.	eps version of the figure
Distribution of the local y unbiased residuals of the pixel end-cap modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution).The local y coordinate of the pixels is along the broad pixel direction.	eps version of the figure
Distribution of the local x unbiased residuals of the SCT barrel modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution). The local x coordinate of the SCT is across the micro-strip direction.	eps version of the figure
Distribution of the local x unbiased residuals of the SCT end-cap modules. Plot produced with tracks (pT> 2 GeV) reconstructed in LHC Minimum Bias events at center of mass energy 7 TeV. Full blue circles show the real data residuals after the detector alignment, and the open red circles show the residuals using MC with a perfectly aligned detector (normalized to the number of entries in the data distribution). The local x coordinate of the SCT is across the micro-strip direction.	eps version of the figure
The TRT unbiased residuals, as obtained from 7 TeV LHC collision data after detector alignment and Monte Carlo (perfectly aligned detector), separately for the barrel and end-caps. The Monte Carlo distributions (open red circles) are normalized to the number of entries in the data (full blue circles). Tracks are required to have pT> 2 GeV. For low-momentum tracks, the width of the residual distribution is expected to be larger than the intrinsic accuracy per hit as predicted from the drifttime measurement because of the contribution from multiple scattering.	eps version of the barrel residuals figure eps version of the endcap residuals figure
Residual maps for the TRT innermost barrel layer using the May 2010 alignment (left) and October 2010 alignment (right). The mean residual is plotted as a function of the global z and ϕ sector position of the reconstructed hit. The z axis is parallel to the straw direction. Coherent misalignments corresponding to barrel module deformations, are uncorrected in the May 2010 and give rise to structure in the mean residual vs z. These misalignments are removed by the wire-by-wire alignment in the October 2010 alignment constants, where the average residuals are centered around zero with no evidence of variation of along the straw.	eps version of the May10 residual maps figure eps version of the Oct10 residual maps figure
TRT end-cap A residual maps for May 2010 alignment (left) and October 2010 alignment (right). The mean residual is plotted as a function of the TRT end-cap wheel number (increasing with increasing global |z|) and ϕ sector position of the reconstructed hit. Coherent misalignments corresponding to end-cap 4-plane wheel deformations, are uncorrected in the May 2010 and give rise to structure in the mean residual vs Phi. These misalignments are removed by the wire-by-wire alignment in the October 2010 alignment constants, where the average residuals are centered around zero with no evidence of variation of along the ϕ sectors.	eps version of the May10 residual maps figure eps version of the Oct10 residual maps figure
TRT end-cap A residual maps for May 2010 alignment (left) and October 2010 alignment (right). The mean residual is plotted as a function of the TRT end-cap wheel number (increasing with increasing global |z|) and the radius of the reconstructed hit. In this view, the straws are radial. Coherent misalignments corresponding to end-cap 4-plane wheel deformations, are uncorrected in the May 2010 and give rise to structure in the mean residual vs position along the straw. The observed alternating pattern is a result of the back-to-back mechanical assembly of the TRT end-cap wheels. These misalignments are removed by the wire-by-wire alignment in the October 2010 alignment constants, where the average residuals are centered around zero with no evidence of variation of along the straw.	eps version of the May10 residual maps figure eps version of the Oct10 residual maps figure

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Responsible: PippaWells
Last reviewed by: -- DanielKollar - 23-Nov-2010