CERN Accelerating science

View of a quadrant of the ID~\cite{Expect} showing each of the major detector elements with their active dimensions and envelopes. The lower part shows a zoomed-in view of the pixel detector region.

Distributions of (a) transverse ($d_0$) and (b) longitudinal ($z_0$) impact parameters of tracks in simulated events. Open squares show tracks reconstructed with the standard algorithm, closed squares show tracks reconstructed with either the standard or second-pass reconstruction algorithm.

Invariant-mass spectrum of the reconstructed secondary vertices, assuming the pion mass for all tracks, in data (points) and MC simulation (solid histogram).

Number of selected secondary vertices in data in the \emph{x--y} plane of the ID. Only vertices with $|\emph{z}| < 400$~mm are considered. For presentation purposes, the background inside the beam pipe is masked out.

Number of selected secondary vertices in data in the $r$--$\phi$~plane of the ID. Only vertices with $|\emph{z}| < 400$~mm are considered.

Number of selected secondary vertices in data in the $r$--$z$~plane of the ID.

Number of selected secondary vertices per event in data (points) and MC simulation (solid histogram), as a function of \emph{r} with $|z| < 700$ mm.

Number of selected secondary vertices per event in data (points) and MC simulation (solid histogram), as a function of ~\emph{z}, (a) for $|z|<700$~mm, and (b) for $|z|>410$~mm, where vertices with $\emph{r} < 50$ mm and $\emph{r} > 155$ mm are excluded to highlight the pixel end-cap region.

Number of selected secondary vertices in data in the \emph{r}--$\phi$ plane of the ID. The radial range corresponds to the SCT inner thermal shield and the first SCT barrel layer.

Number of selected secondary vertices in the local coordinate frame of the pixel module, for (a) data, and (b) MC simulation, in the first barrel layer. The data sample has more events than the simulated sample.

Number of selected secondary vertices in the local coordinate frame of the SCT module, for (a) data and (b) MC simulation, in the first barrel layer. The data sample has more events than the simulated sample.

The total (scalar) sum of the momentum, $\Sigma |\bar{p}|$, of secondary particles from hadronic interactions found in (a) the beryllium part of the beam pipe, and (b) the silicon element in the pixel modules. The data (points) are compared to simulation using two models of hadronic interactions (solid histograms). The number of selected secondary vertices is $N_{\mathrm{SV}}$.

A double ratio of $\Kshort$ yields at different decay distances. The bands are statistical uncertainties from the fits to obtain K$_s$ yields. Details are given in the text.

Ratios of yields of secondary vertices in data to those in MC simulation for the barrel and end-cap regions. The total uncertainties (dotted lines) include both statistical (dark shading) and systematic uncertainties (light shading) in the vertex yields.