D. Montanino

Measurement of differential top-quark pair production cross sections in pp collisions at sqrt(s) = 7 TeV

Normalised differential top-quark-pair production cross sections are measured in pp collisions at a centre-of-mass energy of 7 TeV at the LHC with the CMS detector using data recorded in 2011 corresponding to an integrated luminosity of 5.0 fb−1. The measurements are performed in the lepton+jets decay channels (e+jets and μ+jets) and the dilepton decay channels (e+e−, μ+μ−, and μ±e∓). The tt differential cross section is measured as a function of kinematic properties of the final-state charged leptons and jets associated to b quarks, as well as those of the top quarks and the tt system. The data are compared with several predictions from perturbative QCD calculations up to approximate next-to-next-to-leading-order precision. No significant deviations from the standard model are observed. Submitted to the European Physical Journal C c

Search for supersymmetry in hadronic final states with missing transverse energy using the variables alphaT and b-quark multiplicity in pp collisions at sqrt(s) = 8 TeV

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb−1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950–1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

Search for B0s to mu+ mu- and B0 to mu+ mu- decays

A search for the rare decays Bs → μ+μ− and B0 → μ+μ− is performed in pp collisions at √ s = 7 TeV, with a data sample corresponding to an integrated luminosity of 5 fb−1 collected by the CMS experiment at the LHC. In both decays, the number of events observed after all selection requirements is consistent with the expectation from background plus standard model signal predictions. The resulting upper limits on the branching fractions areB(Bs → μ+μ−) < 7.7× 10−9 andB(B0 → μ+μ−) < 1.8× 10−9 at 95% confidence level. Submitted to the Journal of High Energy Physics ∗See Appendix A for the list of collaboration members ar X iv :1 20 3. 39 76 v2 [ he pex ] 2 3 Ja n 20 13A bstractA search for the rare decays

Measurement of isolated photon production in pp and PbPb collisions at sqrt(s_NN) = 2.76 TeV

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