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