K. Shin

Transverse-Momentum and Pseudorapidity Distributions of Charged Hadrons in pp Collisions at s√=7 TeV

Charged-hadron transverse-momentum and pseudorapidity distributions in protonproton collisions at √ 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 chargedparticle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch/dη||η|<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 √ 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. Published in Physical Review Letters ∗See Appendix A for the list of collaboration members ar X iv :1 00 5. 32 99 v2 [ he pex ] 6 J ul 2 01 0

J/ψ and ψ (2S) production in pp collisions at √s=7Tev

A bstractA measurement of the J/ψ and ψ(2S) production cross sections in pp collisions at

Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at √s=7 TeV

\sqrt {s} = 7{\text{TeV}}

Indications of Suppression of Excited Y States in Pb-Pb Collisions at √sNN = 2.76 TeV

with the CMS experiment at the LHC is presented. The data sample corresponds to an integrated luminosity of 37 pb−1. Using a fit to the invariant mass and decay length distributions, production cross sections have been measured separately for prompt and non-prompt charmonium states, as a function of the meson transverse momentum in several rapidity ranges and integrated in the kinematical regions considered in this study. In addition, cross sections restricted to the acceptance of the CMS detector are given, which are not affected by the polarization of the charmonium states. The ratio of the differential production cross sections of the two states, where systematic uncertainties largely cancel, is also determined. The branching fraction of the inclusive B → ψ(2S)X decay is extracted from the ratio of the non-prompt cross sections to be: