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.
differential cross section; CERN LHC; p nucleus interaction; ALICE; heavy ion scattering