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Schematic cross section through the CMS tracker in the $r$-$z$ plane. Each line-element represents a detector module. Closely spaced double line-elements indicate back-to-back silicon strip modules, in which one module is rotated through a `stereo' angle, so as to permit reconstruction of the hit positions in 3-D. Within a given layer, each module is shifted slightly in $r$ or $z$ with respect to its neighbouring modules, which allows them to overlap, thereby avoiding gaps in the acceptance.

Schematic cross section through the CMS tracker in the $r$-$z$ plane. In this view, the tracker is symmetric about the horizontal line $r=0$, so only the top half is shown here. The centre of the tracker, corresponding to the approximate position of the pp collision point, is indicated by a star. Green dashed lines help the reader understand which modules belong to each of the named tracker subsystems. Strip tracker modules that provide 2-D hits are shown by thin, black lines, while those permitting the reconstruction of hit positions in 3-D are shown by thick, blue lines. The latter actually each consist of two back-to-back strip modules, in which one module is rotated through a `stereo' angle. The pixel modules, shown by the red lines, also provide 3-D hits. Within a given layer, each module is shifted slightly in $r$ or $z$ with respect to its neighbouring modules, which allows them to overlap, thereby avoiding gaps in the acceptance.

Total thickness $t$ of the tracker material traversed by a particle produced at the nominal interaction point, as a function of pseudorapidity $\eta$, expressed in units of radiation length $X_0$ (left) and nuclear interaction length $\lambda_I$ (right). The contribution to the total material budget of each of the subsystems that comprise the CMS tracker is shown, together with contributions from the beam pipe and from the support tube that surrounds the tracker.

Total thickness $t$ of the tracker material traversed by a particle produced at the nominal interaction point, as a function of pseudorapidity $\eta$, expressed in units of radiation length $X_0$ (left) and nuclear interaction length $\lambda_I$ (right). The contribution to the total material budget of each of the subsystems that comprise the CMS tracker is shown, together with contributions from the beam pipe and from the support tube that surrounds the tracker.

The average hit efficiency for layers or disks in the pixel detector excluding defective modules (left), and the average hit efficiency as a function of instantaneous luminosity (right). The peak luminosity ranged from 1 to $4\,\mathrm{nb^{-1}s^{-1}}$ during the data taking.

The average hit efficiency for layers or disks in the pixel detector excluding defective modules (left), and the average hit efficiency as a function of instantaneous luminosity (right). The peak luminosity ranged from 1 to $4\,\mathrm{nb^{-1}s^{-1}}$ during the data taking.

Average hit efficiency for layers or disks in the strip tracker. The black squares show the hit efficiency in all modules, and the red dots for modules included in the readout.

Channel occupancy (labelled by the scale on the right) for CMS silicon detectors in events taken with unbiased triggers with an average of nine pp interactions per beam crossing, displayed as a function of $\eta$, $r$, and $z$.

Fraction of pions produced with $\abs{\eta}<2.5$ that do not undergo a nuclear interaction in the tracker volume, as a function of the number of traversed layers.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Track reconstruction \textit{efficiencies} for \textit{single, isolated muons} (top), \textit{pions} (middle) and \textit{electrons} (bottom) passing the \textit{high-purity} quality requirements. Results are shown as a function of $\eta$ (left), for $\pt = 1$, 10, and 100\GeV. They are also shown as a function of \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively.

Tracking \textit{fake rate} for \textit{single, isolated pions} (top) and \textit{electrons} (bottom) passing \textit{high-purity} quality requirements. Results are shown, as a function of the reconstructed $\eta$ (left), for generated $\pt = 1$, 10, and 100\GeV. Results are also shown as a function of the reconstructed \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. The results for \pt are obtained using particles generated with a flat distribution in $\ln\pt$. NB The measured fake rate depends strongly on the \pt distribution of the generated particles, since, for example, if no particles are generated in a given \pt range, most tracks reconstructed in that range must necessarily be fake. The generated particles used to make the plots of fake rate versus $\eta$ have a different \pt spectrum to those used to make the plots of fake rate versus \pt, therefore the measured fake rates in these two sets of plots are not directly comparable.

Tracking \textit{fake rate} for \textit{single, isolated pions} (top) and \textit{electrons} (bottom) passing \textit{high-purity} quality requirements. Results are shown, as a function of the reconstructed $\eta$ (left), for generated $\pt = 1$, 10, and 100\GeV. Results are also shown as a function of the reconstructed \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. The results for \pt are obtained using particles generated with a flat distribution in $\ln\pt$. NB The measured fake rate depends strongly on the \pt distribution of the generated particles, since, for example, if no particles are generated in a given \pt range, most tracks reconstructed in that range must necessarily be fake. The generated particles used to make the plots of fake rate versus $\eta$ have a different \pt spectrum to those used to make the plots of fake rate versus \pt, therefore the measured fake rates in these two sets of plots are not directly comparable.

Tracking \textit{fake rate} for \textit{single, isolated pions} (top) and \textit{electrons} (bottom) passing \textit{high-purity} quality requirements. Results are shown, as a function of the reconstructed $\eta$ (left), for generated $\pt = 1$, 10, and 100\GeV. Results are also shown as a function of the reconstructed \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. The results for \pt are obtained using particles generated with a flat distribution in $\ln\pt$. NB The measured fake rate depends strongly on the \pt distribution of the generated particles, since, for example, if no particles are generated in a given \pt range, most tracks reconstructed in that range must necessarily be fake. The generated particles used to make the plots of fake rate versus $\eta$ have a different \pt spectrum to those used to make the plots of fake rate versus \pt, therefore the measured fake rates in these two sets of plots are not directly comparable.

Tracking \textit{fake rate} for \textit{single, isolated pions} (top) and \textit{electrons} (bottom) passing \textit{high-purity} quality requirements. Results are shown, as a function of the reconstructed $\eta$ (left), for generated $\pt = 1$, 10, and 100\GeV. Results are also shown as a function of the reconstructed \pt (right), for the barrel, transition, and endcap regions, which are defined by the $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. The results for \pt are obtained using particles generated with a flat distribution in $\ln\pt$. NB The measured fake rate depends strongly on the \pt distribution of the generated particles, since, for example, if no particles are generated in a given \pt range, most tracks reconstructed in that range must necessarily be fake. The generated particles used to make the plots of fake rate versus $\eta$ have a different \pt spectrum to those used to make the plots of fake rate versus \pt, therefore the measured fake rates in these two sets of plots are not directly comparable.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for simulated \textit{$t\bar t$ events} that include superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are for all reconstructed tracks, and also for the subset of tracks passing \textit{high-purity} requirements. The efficiency and fake rate plots are plotted for $\abs{\eta}<2.5$, and the efficiency for charged particles refers to those generated less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for simulated \textit{$t\bar t$ events} that include superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are for all reconstructed tracks, and also for the subset of tracks passing \textit{high-purity} requirements. The efficiency and fake rate plots are plotted for $\abs{\eta}<2.5$, and the efficiency for charged particles refers to those generated less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for simulated \textit{$t\bar t$ events} that include superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are for all reconstructed tracks, and also for the subset of tracks passing \textit{high-purity} requirements. The efficiency and fake rate plots are plotted for $\abs{\eta}<2.5$, and the efficiency for charged particles refers to those generated less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for simulated \textit{$t\bar t$ events} that include superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are for all reconstructed tracks, and also for the subset of tracks passing \textit{high-purity} requirements. The efficiency and fake rate plots are plotted for $\abs{\eta}<2.5$, and the efficiency for charged particles refers to those generated less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are produced for the subset of tracks passing the \textit{high-purity} quality requirements. The efficiency and fake rate plots cover $\abs{\eta}<2.5$. The efficiency results are for charged particles produced less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are produced for the subset of tracks passing the \textit{high-purity} quality requirements. The efficiency and fake rate plots cover $\abs{\eta}<2.5$. The efficiency results are for charged particles produced less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are produced for the subset of tracks passing the \textit{high-purity} quality requirements. The efficiency and fake rate plots cover $\abs{\eta}<2.5$. The efficiency results are for charged particles produced less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is generated randomly from a Poisson distribution with mean value of 8. Plots are produced for the subset of tracks passing the \textit{high-purity} quality requirements. The efficiency and fake rate plots cover $\abs{\eta}<2.5$. The efficiency results are for charged particles produced less than 3\cm (30\cm) from the centre of the beam spot in $r$ ($z$) directions. The efficiency as a function of $\eta$ is for generated particles with $\pt>0.9$\GeV.

Cumulative contributions to the overall tracking performance from the six iterations in track reconstruction. The tracking efficiency for simulated \ttbar events is shown as a function of transverse distance ($r$) from the beam axis to the production point of each particle, for tracks with $\pt > 0.9$\GeV and $\abs{\eta}<2.5$, transverse (longitudinal) impact parameter $<$60 (30)\cm. The reconstructed tracks are required to pass the \textit{high-purity} quality requirements.

Tracking efficiency measured with a tag-and-probe technique, for muons from $\cPZ$ decays, as a function of the muon $\eta$ (left) and the number of reconstructed primary vertices in the event (right) for data (black dots) and simulation (blue bands).

Tracking efficiency measured with a tag-and-probe technique, for muons from $\cPZ$ decays, as a function of the muon $\eta$ (left) and the number of reconstructed primary vertices in the event (right) for data (black dots) and simulation (blue bands).

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated muons} with $\pt = 1$, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and transverse momentum. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated muons} with $\pt = 1$, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and transverse momentum. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated muons} with $\pt = 1$, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and transverse momentum. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated muons} with $\pt = 1$, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and transverse momentum. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated muons} with $\pt = 1$, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and transverse momentum. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for \textit{single, isolated muons} in the barrel, transition, and endcap regions, defined by $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in \pt, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for \textit{single, isolated muons} in the barrel, transition, and endcap regions, defined by $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in \pt, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for \textit{single, isolated muons} in the barrel, transition, and endcap regions, defined by $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in \pt, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for \textit{single, isolated muons} in the barrel, transition, and endcap regions, defined by $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in \pt, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for \textit{single, isolated muons} in the barrel, transition, and endcap regions, defined by $\eta$ intervals of 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in \pt, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated pions} with transverse momenta of 1, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated pions} with transverse momenta of 1, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated pions} with transverse momenta of 1, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated pions} with transverse momenta of 1, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the five track parameters for \textit{single, isolated pions} with transverse momenta of 1, 10, and 100\GeV. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$ and \pt. For each bin in $\eta$, the solid (open) symbols correspond to the half-width for 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $d_0$, $\phi$ and \pt track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the width of the 68\% (90\%) intervals having its origin on the mode of the distribution in residuals, as described in the text. Only the half of the residuals distribution that does contain the non-Gaussian tail due to bremsstrahlung is considered in the interval calculation. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $\cot \theta$ and $z_0$ track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $\cot \theta$ and $z_0$ track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $\cot \theta$ and $z_0$ track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of pseudorapidity}, in the $\cot \theta$ and $z_0$ track parameters for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

\textit{Bias, as a function of pseudorapidity}, on the \pt track parameter for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the mode (mean) of the distribution in residuals. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

\textit{Bias, as a function of pseudorapidity}, on the \pt track parameter for \textit{single, isolated electrons} with $\pt = 10$ and 100\GeV. For each bin in $\eta$, the solid (open) symbols correspond to the mode (mean) of the distribution in residuals. The left (right) plots are of electrons reconstructed with the CTF (GSF) algorithm.

Resolution, \textit{as a function of \pt}, in the five track parameters for charged particles in simulated \textit{$t\bar t$ events} with pileup. The number of pileup interactions superimposed to each simulated event is generated randomly from a Poisson distribution with a mean value of 8. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$, and \pt. For each bin in $\pt$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for charged particles in simulated \textit{$t\bar t$ events} with pileup. The number of pileup interactions superimposed to each simulated event is generated randomly from a Poisson distribution with a mean value of 8. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$, and \pt. For each bin in $\pt$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for charged particles in simulated \textit{$t\bar t$ events} with pileup. The number of pileup interactions superimposed to each simulated event is generated randomly from a Poisson distribution with a mean value of 8. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$, and \pt. For each bin in $\pt$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for charged particles in simulated \textit{$t\bar t$ events} with pileup. The number of pileup interactions superimposed to each simulated event is generated randomly from a Poisson distribution with a mean value of 8. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$, and \pt. For each bin in $\pt$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

Resolution, \textit{as a function of \pt}, in the five track parameters for charged particles in simulated \textit{$t\bar t$ events} with pileup. The number of pileup interactions superimposed to each simulated event is generated randomly from a Poisson distribution with a mean value of 8. From top to bottom and left to right: transverse and longitudinal impact parameters, $\phi$, $\cot \theta$, and \pt. For each bin in $\pt$, the solid (open) symbols correspond to the half-width of the 68\% (90\%) intervals centered on the mode of the distribution in residuals, as described in the text.

The number of additional tracks per event reconstructed after each individual iteration, for \ttbar events generated without pileup and with an average of 8 pileup events. The distributions include only tracks associated with a simulated charged particle.

Primary-vertex resolution in $x$ (left) and in $z$ (right) as a function of the number of tracks at the fitted vertex, for two kinds of events with different average track \pt values (see text).

Primary-vertex resolution in $x$ (left) and in $z$ (right) as a function of the number of tracks at the fitted vertex, for two kinds of events with different average track \pt values (see text).

Primary-vertex reconstruction efficiency as a function of the number of tracks in a cluster, measured in minimum-bias data and in MC simulation.

Pixel tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is randomly generated from a Poisson distribution with mean equal to 8. The two plots of efficiency and fake rate as a function of pseudorapidity are produced applying a $\pt >0.9$\GeV selection.

Pixel tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is randomly generated from a Poisson distribution with mean equal to 8. The two plots of efficiency and fake rate as a function of pseudorapidity are produced applying a $\pt >0.9$\GeV selection.

Pixel tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is randomly generated from a Poisson distribution with mean equal to 8. The two plots of efficiency and fake rate as a function of pseudorapidity are produced applying a $\pt >0.9$\GeV selection.

Pixel tracking \textit{efficiency} (top) and \textit{fake rate} (bottom) for \textit{$t\bar t$ events} simulated with and without superimposed pileup collisions. The number of pileup interactions superimposed on each simulated event is randomly generated from a Poisson distribution with mean equal to 8. The two plots of efficiency and fake rate as a function of pseudorapidity are produced applying a $\pt >0.9$\GeV selection.

\textit{Resolution, as a function of \pt}, in the five track parameters for pixel tracks in simulated \textit{\ttbar events} with pileup in the barrel, transition and endcap regions, defined by the pseudorapidity intervals 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\varphi$, $\cot \vartheta$ and transverse momentum. For each bin in $\pt$, the solid (open) symbol corresponds to the half-width of the 68\% (90\%) interval centered on the most probable value of the residuals distributions.

\textit{Resolution, as a function of \pt}, in the five track parameters for pixel tracks in simulated \textit{\ttbar events} with pileup in the barrel, transition and endcap regions, defined by the pseudorapidity intervals 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\varphi$, $\cot \vartheta$ and transverse momentum. For each bin in $\pt$, the solid (open) symbol corresponds to the half-width of the 68\% (90\%) interval centered on the most probable value of the residuals distributions.

\textit{Resolution, as a function of \pt}, in the five track parameters for pixel tracks in simulated \textit{\ttbar events} with pileup in the barrel, transition and endcap regions, defined by the pseudorapidity intervals 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\varphi$, $\cot \vartheta$ and transverse momentum. For each bin in $\pt$, the solid (open) symbol corresponds to the half-width of the 68\% (90\%) interval centered on the most probable value of the residuals distributions.

\textit{Resolution, as a function of \pt}, in the five track parameters for pixel tracks in simulated \textit{\ttbar events} with pileup in the barrel, transition and endcap regions, defined by the pseudorapidity intervals 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\varphi$, $\cot \vartheta$ and transverse momentum. For each bin in $\pt$, the solid (open) symbol corresponds to the half-width of the 68\% (90\%) interval centered on the most probable value of the residuals distributions.

\textit{Resolution, as a function of \pt}, in the five track parameters for pixel tracks in simulated \textit{\ttbar events} with pileup in the barrel, transition and endcap regions, defined by the pseudorapidity intervals 0--0.9, 0.9--1.4 and 1.4--2.5, respectively. From top to bottom and left to right: transverse and longitudinal impact parameters, $\varphi$, $\cot \vartheta$ and transverse momentum. For each bin in $\pt$, the solid (open) symbol corresponds to the half-width of the 68\% (90\%) interval centered on the most probable value of the residuals distributions.

Pixel vertex position resolutions in $x$ (left) and $z$ (right) as a function of the number of tracks used in the fitted vertex, for minimum-bias and jet-enriched data.

Pixel vertex position resolutions in $x$ (left) and $z$ (right) as a function of the number of tracks used in the fitted vertex, for minimum-bias and jet-enriched data.

Fitted $x_\mathrm{BS}$ (top), $y_\mathrm{BS}$ (middle) and $z_\mathrm{BS}$ (bottom) positions of the centre of the luminous region as a function of time during early 2011 running. The $x_\mathrm{BS}$ and $y_\mathrm{BS}$ values are extracted from the a fit to the $d_{0}$--$\phi$ distribution, and the value of $z_\mathrm{BS}$ is extracted from the fit to the primary-vertex distribution. Each point represents one luminosity section of 23\unit{seconds}. The error bars reflect the statistical uncertainty from the fit.

Fitted $x_\mathrm{BS}$ (top), $y_\mathrm{BS}$ (middle) and $z_\mathrm{BS}$ (bottom) positions of the centre of the luminous region as a function of time during early 2011 running. The $x_\mathrm{BS}$ and $y_\mathrm{BS}$ values are extracted from the a fit to the $d_{0}$--$\phi$ distribution, and the value of $z_\mathrm{BS}$ is extracted from the fit to the primary-vertex distribution. Each point represents one luminosity section of 23\unit{seconds}. The error bars reflect the statistical uncertainty from the fit.

Fitted $x_\mathrm{BS}$ (top), $y_\mathrm{BS}$ (middle) and $z_\mathrm{BS}$ (bottom) positions of the centre of the luminous region as a function of time during early 2011 running. The $x_\mathrm{BS}$ and $y_\mathrm{BS}$ values are extracted from the a fit to the $d_{0}$--$\phi$ distribution, and the value of $z_\mathrm{BS}$ is extracted from the fit to the primary-vertex distribution. Each point represents one luminosity section of 23\unit{seconds}. The error bars reflect the statistical uncertainty from the fit.

Fitted widths $\sigma_x$ (top) and $\sigma_y$ (middle), and length $\sigma_z$ (bottom) of the luminous region as a function of time during early 2011 running, extracted from the fit to the distribution of reconstructed primary vertices. Each point represents one luminosity section of 23~seconds. The error bars reflect the statistical uncertainty from the fit.

Fitted widths $\sigma_x$ (top) and $\sigma_y$ (middle), and length $\sigma_z$ (bottom) of the luminous region as a function of time during early 2011 running, extracted from the fit to the distribution of reconstructed primary vertices. Each point represents one luminosity section of 23~seconds. The error bars reflect the statistical uncertainty from the fit.

Fitted widths $\sigma_x$ (top) and $\sigma_y$ (middle), and length $\sigma_z$ (bottom) of the luminous region as a function of time during early 2011 running, extracted from the fit to the distribution of reconstructed primary vertices. Each point represents one luminosity section of 23~seconds. The error bars reflect the statistical uncertainty from the fit.