Energy dependence of the transverse momentum distributions of charged particles in pp collisions measured by ALICE

Abstract

Differential cross sections of charged particles in inelastic pp collisions as a function of p T have been measured at √s=0.9, 2.76 and 7 TeV at the LHC. The p T spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual √s cannot be described by NLO-pQCD, the relative increase of cross section with √s is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at √s=2.76 and 5.02 TeV up to p T=50 GeV/c as required for the calculation of the nuclear modification factor in nucleus–nucleus and proton–nucleus collisions.