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noimgNumber of events for each multiplicity bin used in the 7 TeV analysis with total integrated luminosity of 980~nb$^{-1}$. The multiplicity of offline reconstructed tracks, $N_\mathrm{trk}^\mathrm{offline}$, was counted within the kinematic cuts of $|\eta|<2.4$ and $p_{T}>0.4\GeVc$. The last two columns list the average values of $N_\mathrm{trk}^\mathrm{offline}$ as well as the average of $N_\mathrm{trk}^\mathrm{corrected}$, the event multiplicity corrected for all detector and algorithm inefficiencies. \\

Distributions of the number of tracks reconstructed in offline analysis, $N_\mathrm{trk}^\mathrm{offline}$, for minimum bias events, as well as high-multiplicity triggered events, both at 7~TeV, with online multiplicity $N_\mathrm{trk}^\mathrm{online}$ greater than (a) 70 and (b) 85. The total integrated luminosity of the data set is 980~nb$^{-1}$. The minimum bias trigger was heavily prescaled during higher luminosity LHC running. The HLT efficiency turn-on curves for the two high multiplicity triggers are shown in the two panels at the bottom.

Two-particle correlation functions versus $\Delta \eta$ and $\Delta \phi$ in $pp$ collisions at $\sqrt{s} =$ (a) 0.9, (b) 2.36, and (c) 7~TeV.

Two-particle correlation functions versus $\Delta \eta$ and $\Delta \phi$ in PYTHIA D6T tune at $\sqrt{s} =$ (a) 0.9, (b) 2.36, and (c) 7~TeV.

Two-particle pseudorapidity correlation function, obtained by averaging over the entire $\Delta \phi$ range from $0$ to $\pi$, in $pp$ collisions at $\sqrt{s} =$ (a) 0.9, (b) 2.36, and (c) 7~TeV. The solid curves correspond to the fits by the cluster model using Eq.~(\ref{2pcorr_clusterfitting_incl}). Error bars are smaller than the symbols.

(a) $K_{\rm eff}$ and (b) $\delta$ as a function of $\sqrt{s}$, measured for $p_{T}>0.1\GeVc$ and $|\eta|<2.4$ by CMS in solid circles. Open circles show the PYTHIA results with the D6T tune.

(a) $K_{\rm eff}$ and (b) $\delta$ as a function of $\sqrt{s}$ based on a model-dependent extrapolation of CMS data to $p_T\approx 0$ and $|\eta|<3$ (solid circles), as well as data from PHOBOS~\cite{Alver:2007wy} (solid squares), UA5~\cite{Ansorge:1988fg} (solid triangles) and ISR \cite{Eggert:1974ek} (solid stars) experiments for $pp$ and $p\bar{p}$ collisions. Open circles and squares show the PYTHIA results for the D6T tune and default parameters, respectively.

2-D two-particle correlation functions for 7~TeV $pp$ (a) minimum bias events with $p_{T}>0.1\GeVc$, (b) minimum bias events with $1 < p_{T} < 3\GeVc$, (c) high multiplicity ($N_\mathrm{trk}^\mathrm{offline} \geq 110$) events with $p_{T}>0.1\GeVc$ and (d) high multiplicity ($N_\mathrm{trk}^\mathrm{offline} \geq 110$) events with $1<p_{T}<3\GeVc$. The sharp near-side peak from jet correlations is cut off in order to better illustrate the structure outside that region.

Projections of 2-D correlation functions onto $\Delta\phi$ for $2.0<|\Delta\eta|<4.8$ in different $p_{T}$ and multiplicity bins for fully corrected 7~TeV $pp$ data and reconstructed PYTHIA8 simulations. Error bars are smaller than the symbols.

Associated yield for the near-side of the correlation function integrated over the region of $2.0<|\Delta\eta|<4.8$ as a function of event multiplicity in bins of $p_{T}$ for 7~TeV $pp$ collisions. The error bars correspond to statistical errors, while the brackets around the data points denote the systematic uncertainties. The open squares show results for PYTHIA8.

Like-sign and unlike-sign associated yield for the near-side of the correlation function integrated over the region of $2.0<|\Delta\eta|<4.8$ as a function of event multiplicity in bins of $p_{T}$. The error bars correspond to statistical errors, while the brackets around the data points denote the systematic uncertainties.