Measurement of the t(t)over-bar production cross section in the all-jets final state in pp collisions at root s=8TeV
Marie-Curie programme ; European Research Council ; EPLANET (European Union) ; Leventis Foundation ; A. P. Sloan Foundation ; Alexander von Humboldt Foundation ; Belgian Federal Science Policy Office ; Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium) ; Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium) ; Ministry of Education, Youth and Sports (MEYS) of the Czech Republic ; Council of Science and Industrial Research, India ; HOMING PLUS programme of the Foundation for Polish Science ; European Union, Regional Development Fund ; OPUS programme of the National Science Center (Poland) ; Compagnia di San Paolo (Torino) ; Consorzio per la Fisica (Trieste) ; MIUR project (Italy) ; Thalis programme - EU-ESF ; Aristeia programme - EU-ESF ; Greek NSRF ; National Priorities Research Program by Qatar National Research Fund ; Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand) ; Welch Foundation ; MIUR project (Italy): 20108T4XTM ; Welch Foundation: C-1845 ; The cross section for tt production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 TeV at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4 fb(-1). The inclusive cross section is found to be 275.6 +/- 6.1 (stat) +/- 37.8 (syst) +/- 7.2 (lumi) pb. The normalized differential cross sections are measured as a function of the top quark transverse momenta, pT, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark pT spectra are significantly softer than theoretical predictions.