Charged-particle multiplicities in pp interactions measured with the ATLAS detector at the LHC

Aad, G and Abbott, B. and Abdallah, J. and Abdelalim, A .A. and Abdesselam, A. and Abdinov, O. and Abi, B. and Abolins, M. and Bell, William, The ATLAS collaboration (2011) Charged-particle multiplicities in pp interactions measured with the ATLAS detector at the LHC. New Journal of Physics, 13 (053033). 053033. ISSN 1367-2630 (https://doi.org/10.1088/1367-2630/13/5/053033)

[thumbnail of Aad-etal-NJP2011-Charged-particle-multiplicities-pp-interactions-measured-ATLAS-detector-LHC]
Preview
 Text. Filename: Aad_etal_NJP2011_Charged_particle_multiplicities_pp_interactions_measured_ATLAS_detector_LHC.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo
Download (1MB)| Preview

Abstract

Measurements are presented from proton–proton collisions at centre-of-mass energies of , 2.36 and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections. The results are compared to each other and to various Monte Carlo (MC) models, including a new AMBT1 pythia6 tune. In all the kinematic regions considered, the particle multiplicities are higher than predicted by the MC models. The central charged-particle multiplicity per event and unit of pseudorapidity, for tracks with pT>100 MeV, is measured to be 3.483±0.009 (stat)±0.106 (syst) at and 5.630±0.003 (stat)±0.169 (syst) at .

ORCID iDs

Aad, G, Abbott, B., Abdallah, J., Abdelalim, A .A., Abdesselam, A., Abdinov, O., Abi, B., Abolins, M. and Bell, William ORCID logoORCID: https://orcid.org/0000-0002-0138-8639;
CORE (COnnecting REpositories)