Pseudorapidity distributions of charged particles as a function of mid and forward rapidity mutiplicities in pp collisions at $\sqrt{s}$ = 5.02, 7 and 13 TeV

TL;DR

This paper reports on the measurement of pseudorapidity distributions of charged particles in proton-proton collisions at various energies, analyzing how these distributions depend on multiplicity in mid and forward rapidity regions, and compares results with event generator predictions.

Contribution

It provides new measurements of pseudorapidity densities at multiple energies and compares these with PYTHIA 8 and EPOS LHC models, highlighting their agreement with data.

Findings

Both PYTHIA 8 and EPOS LHC accurately describe the data.

Forward rapidity multiplicity estimators are less affected by autocorrelations.

Results extend understanding of particle production in pp collisions.

Abstract

The multiplicity dependence of the pseudorapidity density of charged particles in proton-proton (pp) collisions at centre-of-mass energies $\sqrt{s}$ = 5.02, 7 and 13 TeV measured by ALICE is reported. The analysis relies on track segments measured in the midrapidity range ($|\eta| < 1.5$). Results are presented for inelastic events having at least one charged particle produced in the pseudorapidity interval $|\eta|<1$ ($\mathrm{INEL}_{>0}$). The multiplicity dependence of the pseudorapidy density of charged particles is measured with mid and forward rapidity multiplicity estimators, the latter being less affected by autocorrelations. A detailed comparison with predictions from the PYTHIA 8 and EPOS LHC event generators is also presented. Both generators provide a good description of the data.