D. Kcira

Measurements of inclusive W and Z cross sections in pp collisions at √s=7 TeV

Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.Measurements of inclusive W and Z boson production cross sections in pp collisions at

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

\sqrt {s} = 7

Stand-alone Cosmic Muon Reconstruction Before Installation of the CMS Silicon Strip Tracker

TeV are presented, based on 2.9 pb−1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give

Dijet Azimuthal Decorrelations in pp Collisions at √[s]=7 TeV

\sigma \left( {{\text{pp}} \to {\text{W}}X} \right) \times \mathcal{B}\left( {{\text{W}} \to \ell \nu } \right) = 9.95\pm 0.07\left( {{\text{stat}}{.}} \right)\pm 0.28\left( {{\text{syst}}{.}} \right)\pm 1.09

Alignment of the CMS silicon strip tracker during stand-alone commissioning

(lumi.) nb and

Measurements of tt¯ spin correlations and top quark polarization using dilepton final states in pp collisions at √s=8 TeV

\sigma \left( {{\text{pp}} \to {\text{Z}}X} \right) \times \mathcal{B}\left( {Z \to {\ell^{+} }{\ell^{-} }} \right) = 0.931\pm 0.026\left( {{\text{stat}}{.}} \right)\pm 0.023\left( {{\text{syst}}{.}} \right)\pm 0.102

Measurement of the W-boson helicity in top-quark decays from tt⁻ production in lepton+jets events in pp collisions at √s=7 TeV

(lumi.) nb, where ℓ stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.40 paginas, 8 figuras, 5 tablas.-- Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- CMS Collaboration: et al.

Search for Pair Production of First-Generation Scalar Leptoquarks in

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

pp

The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15% of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses. Comment: Added missing LaTex command / no change in contents w.r.t. v1

Collisions at

Measurements of dijet azimuthal decorrelations in pp collisions at √ s = 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 pb−1. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation. Submitted to Physical Review Letters ∗See Appendix A for the list of collaboration members ar X iv :1 10 1. 50 29 v2 [ he pex ] 2 1 A pr 2 01 1