A measurement of the cross section for the production of topquark–antiquark pairs(tt) inassociation with a vector boson V (W or Z) in proton-proton collisions at sqrt(s)=8 TeV is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb−1 recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and μ) channels: a same- sign dilepton analysis targeting ttW events, and trilepton and four-lepton analyses designed for ttZ events. In the same- sign dilepton channel, the ttW cross section is measured as σttW=170+90−80(stat)±70(syst)fb, corresponding to a significance of 1.6 standard deviations over the background-only hypothesis. Combining the trilepton and four-leptonchannels, a direct measurement of the ttZ cross section, σttZ=200+80−70(stat)+40−30(syst)fb−1, is obtained with a significance of 3.1 standard deviations. The measured cross sections are compatible with standard model predictions within their experimental uncertainties. The inclusive ttV process is observed with a significance of 3.7 standard deviations from the combination of all three leptonic channels.

V. Khachatryan, A. M. Sirunyan, A. Tumasyan, W. Adam, T. Bergauer, M. Dragicevic, et al. (2014). Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at sqrt(s) = 8 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 74, 3060-3086 [10.1140/epjc/s10052-014-3060-7].

Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at sqrt(s) = 8 TeV

BONACORSI, DANIELE;BRAIBANT, SYLVIE;BRIGLIADORI, LUCA;CAMPANINI, RENATO;CAPILUPPI, PAOLO;CASTRO, ANDREA;CODISPOTI, GIUSEPPE;CUFFIANI, MARCO;FANFANI, ALESSANDRA;FASANELLA, DANIELE;GUIDUCCI, LUIGI;PRIMAVERA, FEDERICA;ROVELLI, TIZIANO;SIROLI, GIAN PIERO;TOSI, NICOLÒ;C. Battilana;
2014

Abstract

A measurement of the cross section for the production of topquark–antiquark pairs(tt) inassociation with a vector boson V (W or Z) in proton-proton collisions at sqrt(s)=8 TeV is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb−1 recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and μ) channels: a same- sign dilepton analysis targeting ttW events, and trilepton and four-lepton analyses designed for ttZ events. In the same- sign dilepton channel, the ttW cross section is measured as σttW=170+90−80(stat)±70(syst)fb, corresponding to a significance of 1.6 standard deviations over the background-only hypothesis. Combining the trilepton and four-leptonchannels, a direct measurement of the ttZ cross section, σttZ=200+80−70(stat)+40−30(syst)fb−1, is obtained with a significance of 3.1 standard deviations. The measured cross sections are compatible with standard model predictions within their experimental uncertainties. The inclusive ttV process is observed with a significance of 3.7 standard deviations from the combination of all three leptonic channels.
2014
V. Khachatryan, A. M. Sirunyan, A. Tumasyan, W. Adam, T. Bergauer, M. Dragicevic, et al. (2014). Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at sqrt(s) = 8 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 74, 3060-3086 [10.1140/epjc/s10052-014-3060-7].
V. Khachatryan;A. M. Sirunyan;A. Tumasyan;W. Adam;T. Bergauer;M. Dragicevic;J. Erö;C. Fabjan;M. Friedl;R. Frühwirth;V. M. Ghete;C. Hartl;N. Hörmann;J....espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/375251
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