Measurement of the t(t)over-bar production cross section in pp collisions at root s=7 TeV using the kinematic properties of events with leptons and jets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination of jet energy calibration and transverse momentum resolution in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exclusive gamma gamma -> mu(+)mu(-) production in proton-proton collisions at root s=7TeV

A measurement of the exclusive two-photon production of muon pairs in proton-proton collisions at root s = 7 TeV, pp -> p mu(+)mu(-) p, is reported using data corresponding to an integrated luminosity of 40 pb-1. For muon pairs with invariant mass greater than 11.5 GeV, transverse momentum p(T)(mu) > 4 GeV and pseudorapidity 1770.1) < 2.1, a fit to the dimuon p(T)(mu(+)mu(-)) distribution results in a measured cross section of sigma(p -> p mu(+)mu(-) p) - 3.38(-0.55)(+0.58) (stat.)+/- 0.16 (syst.) +/- 0.14 (lumi.) pb, consistent with the theoretical prediction evaluated with the event generator LPAIR. The ratio to the predicted cross section is 0.83+(0.14)(-0.13) (stat.) +/- 0.04 (syst.) +/- 0.03 (lumi.). The characteristic distributions of the muon pairs produced via Ty fusion, such as the muon acoplanarity, the muon pair invariant mass and transverse momentum agree with those from the theory.

Measurement of the production cross section for pairs of isolated photons in pp collisions at root s=7 TeV

The integrated and differential cross sections for the production of pairs of isolated photons is measured in proton-proton collisions at a centre-of-mass energy of 7TeV with the CMS detector at the LHC. A data sample corresponding to an integrated luminosity of 36 pb(-1) is analysed. A next-to-leading-order perturbative QCD calculation is compared to the measurements. A discrepancy is observed for regions of the phase space where the two photons have an azimuthal angle difference Delta phi less than or similar to 2.8 rad.

Search for the standard model Higgs boson in the H -> ZZ -> 2l2v channel in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of high-p(T) charged particle suppression in PbPb compared to pp collisions at root s(NN)=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Performance of tau-lepton reconstruction and identification in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for B-S(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-) decays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inclusive b-jet production in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for quark compositeness in dijet angular distributions from pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the inclusive production cross sections for forward jets and for dijet events with one forward and one central jet in pp collisions at root s=7 TeV

The inclusive production cross sections for forward jets, as well for jets in dijet events with at least one jet emitted at central and the other at forward pseudorapidities, are measured in the range of transverse momenta p(T) = 35-150 GeV/c in proton-proton collisions at root s = 7 TeV by the CMS experiment at the LHC. Forward jets are measured within pseudorapidities 3.2<|eta|<4.7, and central jets within the |eta|<2.8 range. The double differential cross sections with respect to pt and eta are compared to predictions from three approaches in perturbative quantum chromodynamics: (i) next-to-leading-order calculations obtained with and without matching to parton-shower Monte Carlo simulations, (ii) PYTHIA and HERWIG parton-shower event generators with different tunes of parameters, and (iii) CASCADE and HEJ models, including different non-collinear corrections to standard single-parton radiation. The single-jet inclusive forward jet spectrum is well described by all models, but not all predictions are consistent with the spectra observed for the forward-central dijet events.

Measurement of the mass difference between top and antitop quarks

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the cross section for production of b(b)over-barX decaying to muons in pp collisions at root s=7TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the Z/gamma* plus b-jet cross section in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)