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Transverse-momentum and pseudorapidity distributions of charged hadrons in collisions at sqrt(s) = 7 TeV

Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at sqrt(s)=7  TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch/deta|eta|<0.5=5.78+/-0.01(stat)+/-0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from sqrt(s)=0.9 to 7 TeV is [66.1+/-1.0(stat)+/-4.2(syst)]%. The mean transverse momentum is measured to be 0.545+/-0.005(stat)+/-0.015(syst)  GeV/c. The results are compared with similar measurements at lower energies.

LHC; CMS; Physics; Particle Physics

The CMS Collaboration