Hit-multiplicity distribution in the VELO for selected events of the minimum-bias samples in the (left) $ p + \mathrm{Pb}$ and (right) $\mathrm{Pb} + p$ configurations. The activity classes are defined as fractions of the full distribution, as indicated by colours (shades). The $0-3\%$ class is a sub-sample of the $0-10\%$ class.

Two-particle correlation functions for events recorded in the $ p + \mathrm{Pb}$ configuration, showing the (left) low and (right) high event-activity classes. The analysed pairs of prompt charged particles are selected in a $p_{\mathrm{ T}}$ range of $1-2 {\mathrm{ Ge V /}c} $. The near-side peak around $\Delta\eta=\Delta\phi=0$ is truncated in the histograms.

Two-particle correlation functions for events recorded in the $\mathrm{Pb} + p$ configuration, showing the (left) low and (right) high event-activity classes. The analysed pairs of prompt charged particles are selected in a $p_{\mathrm{ T}}$ range of $1-2 {\mathrm{ Ge V /}c} $. The near-side peak around $(\Delta\eta=\Delta\phi=0)$ is truncated in the histograms.

Two-particle correlation functions for events recorded in the $ p + \mathrm{Pb}$ (left) and $\mathrm{Pb} + p$ (right) configurations, showing the $0-3\%$ event-activity class. The analysed pairs of prompt charged particles are selected in a $p_{\mathrm{ T}}$ range of $2-3 {\mathrm{ Ge V /}c} $. The near-side peak around $(\Delta\eta=\Delta\phi=0)$ is truncated in each histogram.

One-dimensional correlation yield as a function of $\Delta\phi$ obtained from the ZYAM-method by averaging over $2.0<\Delta\eta<2.9$. The subtracted yields are presented for $\sqrt{s_{\scriptscriptstyle N N}}=5\mathrm{ Te V} $ proton-lead collisions recorded in $ p + \mathrm{Pb}$ (full green circles) and $\mathrm{Pb} + p$ (open blue circles) configurations. The ZYAM constant is given in each panel. Event classes are compared for low to very-high activities from top to bottom, and different intervals of increasing $ p_{\mathrm{ T}} $ from left to right. Only statistical uncertainties are shown. Error bars are often smaller than the markers.

One-dimensional correlation yield as a function of $\Delta\phi$ obtained from the ZYAM-method by averaging the two-dimensional distribution over $2.0<\Delta\eta<2.9$. The results for the $ p + \mathrm{Pb}$ and $\mathrm{Pb} + p$ samples are compared in five event classes which probe identical activities in the range $2.0<\eta<4.9$. The measured hit-multiplicities of the $ p + \mathrm{Pb}$ sample are scaled to agree with the hit-multiplicities of the $\mathrm{Pb} + p$ sample. The uncertainty band represents the systematic limitation of the scaling procedure. The error bars represent the statistical uncertainty.

Animated gif made out of all figures.

Relative event-activity classes defined by the VELO -hit multiplicity, $\mathcal N^{\mathrm{hit}}_{{\scriptscriptstyle \text{VELO }}}$ , of an event. The classes are defined as fractions of the $\mathcal N^{\mathrm{hit}}_{{\scriptscriptstyle \text{VELO }}}$ distribution for minimum-bias recorded events in the $ p + \mathrm{Pb}$ or $\mathrm{Pb} + p$ configuration. The $0-3\%$ class is a sub-sample of the $0-10\%$ class. For illustration purposes the average number, $\langle N_{ch} \rangle_{\text{MC}}$, of prompt charged particles with $ p >2 {\mathrm{ Ge V /}c} $, $ p_{\mathrm{ T}} >0.15 {\mathrm{ Ge V /}c} $ and $2.0<\eta<4.9$ is listed for events simulated with the Hijing event generator. Statistical uncertainties are negligible.

Common absolute activity bins for the $ p + \mathrm{Pb}$ and $\mathrm{Pb} + p$ samples. The activity of $ p + \mathrm{Pb}$ events is scaled to match the same activity ranges of $\mathrm{Pb} + p$ events, as explained in the text. For illustration purposes the average number, $\langle N_{ch} \rangle_{\text{MC}}$, of prompt charged particles with $ p >2 {\mathrm{ Ge V /}c} $, $ p_{\mathrm{ T}} >0.15 {\mathrm{ Ge V /}c} $ and $2.0<\eta<4.9$ is listed for events simulated with the Hijing event generator. The uncertainties are due to the scaling factor of $0.77 \pm 0.08$. Statistical uncertainties are negligible.