Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s = 0.9 and 2.36TeV

Abstract

Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at √s = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0:46 ± 0:01 (stat.) ± 0.01 (syst.) GeV/c at 0.9 TeV and 0:50 ± 0:01 (stat.) ± 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2:4 and +2:4. At these energies, the measured pseudorapidity densities in the central region, dNch/dη| |η|>0.5, are 3:48±0:02 (stat.) ± 0.13 (syst.) and 4:47±0:04 (stat.) ± 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and con- firm the expectation of near equal hadron production in pp̄ and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date.