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- Gabinete de Informação e Atendimento à Vítima: Espaço Cidadania e JustiçaPublication . Neves, A.; Fernandes, B.; Baúto, R.; Saramago, M.; Almeida, I.
- Measurement of the cross-section for W boson production in association with b-jets in pp collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detectorPublication . ATLAS collaboration (2911 authors); Aguilar-Saavedra, Juan Antonio; Amor Dos Santos, Susana Patricia; Anjos, Nuno; Cantrill, Robert; Carvalho, João; Castro, Nuno Filipe; Conde Muiño, Patricia; Da Cunha Sargedas De Sousa, Mario Jose; Do Valle Wemans, André; Fiolhais, Miguel; Galhardo, Bruno; Gomes, Agostinho; Gonçalo, Ricardo; Jorge, Pedro; Lopes, Lourenco; Machado Miguens, Joana; Maio, Amélia; Maneira, José; Oliveira, Miguel Alfonso; Onofre, António; Palma, Alberto; Pina, João Antonio; Pinto, Belmiro; Santos, Helena; Saraiva, João; Silva, José; Veloso, Filipe; Wolters, HelmutThis paper reports a measurement of the W+b-jets (W+b+X and W+$b\bar{b}$ +X) production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. These results are based on data corresponding to an integrated luminosity of 4.6 fb$^{-1}$, collected with the ATLAS detector. Cross-sections are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. The W+b-jets cross-section, corrected for all known detector eects, is quoted in a limited kinematic range. Combining the muon and electron channels, the ducial cross-section for W+b-jets is measured to be 7.1 $\pm$ 0.5 (stat) $\pm$ 1.4 (syst) pb, consistent with the next-to-leading order QCD prediction, corrected for non-perturbative and double-parton interactions (DPI) contributions, of 4.7 $\pm$ 0.09 (stat) $^{+0.60}_{-0.49}$ (scale) $\pm$ 0.06 (PDF) $\pm$ 0.16 (non-pert) $^{+0.52}_{-0.38}$ (DPI) pb.
- Observation of a new boson with mass near 125 GeV in pp collisions at $\sqrt{s}$ = 7 and 8 TeVPublication . CMS collaboration (2188 authors); Hollar, Jonathan; Nayak, Aruna; Calpas, Betty; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Musella, Pasquale; Rodrigues Antunes, Joao; Silva, Pedro; Pela, Joao; Leonardo, NunoA detailed description is reported of the analysis used by the CMS Collaboration in the search for the standard model Higgs boson in pp collisions at the LHC, which led to the observation of a new boson. The data sample corresponds to integrated luminosities up to 5.1 inverse femtobarns at $\sqrt{s}$ = 7 TeV, and up to 5.3 inverse femtobarns at $\sqrt{s}$ = 8 TeV. The results for five Higgs boson decay modes $\gamma\gamma, ZZ, WW, \tau \tau$, and bb, which show a combined local significance of 5 standard deviations near 125 GeV, are reviewed. A fit to the invariant mass of the two high resolution channels, gamma gamma and ZZ to 4 ell, gives a mass estimate of 125.3 +/- 0.4 (stat) +/- 0.5 (syst) GeV. The measurements are interpreted in the context of the standard model Lagrangian for the scalar Higgs field interacting with fermions and vector bosons. The measured values of the corresponding couplings are compared to the standard model predictions. The hypothesis of custodial symmetry is tested through the measurement of the ratio of the couplings to the W and Z bosons. All the results are consistent, within their uncertainties, with the expectations for a standard model Higgs boson.