Charged-particle distributions in $\sqrt{s}=13$ TeV $pp$ interactions measured with the ATLAS detector at the LHC

TL;DR

This paper reports detailed measurements of charged-particle distributions in 13 TeV proton-proton collisions at the LHC, providing data to test and refine theoretical models of particle production.

Contribution

It presents new high-precision measurements of charged-particle multiplicities and momentum distributions at 13 TeV, including comparisons with Monte Carlo simulations.

Findings

Distributions are measured for particles with pT > 500 MeV and |η| < 2.5.

Results are corrected for detector effects and presented at particle level.

Data are compared with various Monte Carlo event generator predictions.

Abstract

Charged-particle distributions are measured in proton-proton collisions at a centre-of-mass energy of 13 TeV, using a data sample of nearly 9 million events, corresponding to an integrated luminosity of 170 $\mu$b$^{-1}$, recorded by the ATLAS detector during a special Large Hadron Collider fill. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on the charged-particle multiplicity are presented. The measurements are performed with charged particles with transverse momentum greater than 500 MeV and absolute pseudorapidity less than 2.5, in events with at least one charged particle satisfying these kinematic requirements. Additional measurements in a reduced phase space with absolute pseudorapidity less than 0.8 are also presented, in order to compare with other experiments. The results are corrected for detector effects, presented as particle-level distributions and are compared to the predictions of various Monte Carlo event generators.