The Fourier coeffcients v2and v3characterizing the anisotropy of the azimuthal distribution of charged particles produced in PbPb collisions at √sNN= 5.02 TeV are measured with data collected by the CMS experiment. The measurements cover a broad transverse momentum range, 1 10 GeV/c range, where anisotropic azimuthal distributions should reflect the path-length dependence of parton energy loss in the created medium. Results are presented in several bins of PbPb collision centrality, spanning the 60% most central events. The v2coeffcient is measured with the scalar product and the multiparticle cumulant methods, which have different sensitivities to initial-state fluctuations. The values from both methods remain positive up to pT∼ 60–80 GeV/c, in all examined centrality classes. The v3coeffcient, only measured with the scalar product method, tends to zero for pT>~ 20 GeV/c. Comparisons between theoretical calculations and data provide new constraints on the path-length dependence of parton energy loss in heavy ion collisions and highlight the importance of the initial-state fluctuations. ; Individuals have received support from the Marie-Curie program and the European Research Council and EPLANET (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Programa Clarín-COFUND del Principado de Asturias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation, contract C-1845. ; Peer Reviewed
Austrian Federal Ministry of Science, Research and Economy and the Austrian Science Fund ; Belgian Fonds de la Recherche Scientifique, and Fonds voor Wetenschappelijk Onderzoek ; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; Bulgarian Ministry of Education and Science ; CERN ; Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China ; Colombian Funding Agency (COLCIENCIAS) ; Croatian Ministry of Science, Education and Sport, and the Croatian Science Foundation ; Research Promotion Foundation, Cyprus ; Ministry of Education and Research, Estonian Research Council ; European Regional Development Fund, Estonia ; Academy of Finland, Finnish Ministry of Education and Culture, and Helsinki Institute of Physics ; Institut National de Physique Nucleaire et de Physique des Particules / CNRS, and Commissariat lI'Energie Atomique et Energies Alternatives / CEA, France ; Bundesministerium fur Bildung und Forschung, Deutsche Forschungsgemeinschaft, and Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany ; General Secretariat for Research and Technology, Greece ; National Scientific Research Foundation, and National Innovation Office, Hungary ; Department of Atomic Energy and the Department of Science and Technology, India ; Institute for Studies in Theoretical Physics and Mathematics, Iran ; Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy ; Ministry of Science, ICT and Future Planning, and National Research Foundation (NRF), Republic of Korea ; Lithuanian Academy of Sciences ; Ministry of Education, and University of Malaya (Malaysia) ; Mexican Funding Agencies (CINVESTAV, CONACYT, SEP, and UASLP-FAI) ; Ministry of Business, Innovation and Employment, New Zealand ; Pakistan Atomic Energy Commission; the Ministry of Science and Higher Education and the National Science Centre, Poland ; Fundacao para a Ciencia e a Tecnologia, Portugal; JINR, Dubna; ; Secretaria de Estado de Investigacion, Desarrollo e Innovacion and Programa Consolider-Ingenio 2010, Spain ; Swiss Funding Agencies (ETH Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and SER); the Ministry of Science and Technology, Taipei ; Thailand Center of Excellence in Physics, the Institute for the Promotion of Teaching Science and Technology of Thailand, Special Task Force for Activating Research and the National Science and Technology Development Agency of Thailand ; Scientific and Technical Research Council of Turkey, and Turkish Atomic Energy Authority ; National Academy of Sciences of Ukraine, and State Fund for Fundamental Researches, Ukraine ; Science and Technology Facilities Council, UK ; US Department of Energy, and the US National Science Foundation. Individuals have received support from the Marie-Curie programme and the European Research Council and EPLANET (European Union) ; Leventis Foundation; the A. P. Sloan Foundation ; Alexander von Humboldt Foundation ; Belgian Federal Science Policy Office ; Fonds pour la Formation 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, cofinanced from European Union, Regional Development Fund ; Compagnia di San Paolo (Torino) ; Consorzio per la Fisica (Trieste) ; MIUR project ; Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF ; National Priorities Research Program by Qatar National Research Fund ; Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand) ; Welch Foundation ; Science and Technology Facilities Council ; MIUR project: 20108T4XTM ; Science and Technology Facilities Council: GRIDPP ; Science and Technology Facilities Council: ST/N000250/1 ; Science and Technology Facilities Council: CMS ; Science and Technology Facilities Council: ST/K001256/1 ; A measurement of the top quark pair production () cross section in proton-proton collisions at the centre-of-mass energy of 8 is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6. This analysis is performed in the decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured cross section is . This measurement is compared with an analysis of 7 data, corresponding to an integrated luminosity of 5.0, to determine the ratio of 8 to 7 cross sections, which is found to be . The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.
Austrian Federal Ministry of Science, Research and Economy ; Austrian Science Fund ; Belgian Fonds de la Recherche Scientifique ; Fonds voor Wetenschappelijk Onderzoek ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; Bulgarian Ministry of Education and Science ; CERN ; Chinese Academy of Sciences, Ministry of Science and Technology ; National Natural Science Foundation of China ; Colombian Funding Agency (COLCIENCIAS) ; Croatian Ministry of Science, Education and Sport ; Croatian Science Foundation ; Research Promotion Foundation, Cyprus ; Secretariat for Higher Education, Science, Technology, and Innovation, Ecuador ; Ministry of Education and Research, Estonian Research Council ; European Regional Development Fund, Estonia ; Academy of Finland, Finnish Ministry of Education and Culture ; Helsinki Institute of Physics ; Institut National de Physique Nucleaire et de Physique des Particules/CNRS ; Commissariat a l'Energie Atomique et aux Energies Alternatives/CEA, France ; Bundesministerium fur Bildung und Forschung ; Deutsche Forschungsgemeinschaft ; Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany ; General Secretariat for Research and Technology, Greece ; National Scientific Research Foundation ; National Innovation Office, Hungary ; Department of Atomic Energy ; Department of Science and Technology, India ; Institute for Studies in Theoretical Physics and Mathematics, Iran ; Science Foundation, Ireland ; Istituto Nazionale di Fisica Nucleare, Italy ; Ministry of Science, ICT, and Future Planning ; National Research Foundation (NRF), Republic of Korea ; Lithuanian Academy of Sciences ; Ministry of Education ; University of Malaya (Malaysia) ; Mexican Funding Agency (BUAP) ; Mexican Funding Agency (CINVESTAV) ; Mexican Funding Agency (CONACYT) ; Mexican Funding Agency (LNS) ; Mexican Funding Agency (SEP) ; Mexican Funding Agency (UASLP-FAI) ; Ministry of Business, Innovation and Employment, New Zealand ; Pakistan Atomic Energy Commission ; Ministry of Science and Higher Education ; National Science Centre, Poland ; Fundaciio para a Ciencia e a Tecnologia, Portugal ; JINR, Dubna ; Ministry of Education and Science of the Russian Federation ; Federal Agency of Atomic Energy of the Russian Federation ; Russian Academy of Sciences ; Russian Foundation for Basic Research ; Ministry of Education, Science and Technological Development of Serbia ; Secretaria de Estado de Investigacion ; Desanrrollo e Innovacion and Programa Consolider-Ingenio, Spain ; Swiss Funding Agency (ETH Board) ; Swiss Funding Agency (ETH Zurich) ; Swiss Funding Agency (PSI) ; Swiss Funding Agency (SNF) ; Swiss Funding Agency (UniZH) ; Swiss Funding Agency (Canton Zurich) ; Swiss Funding Agency (SER) ; Ministry of Science and Technology, Taipei ; Thailand Center of Excellence in Physics ; Institute for the Promotion of Teaching Science and Technology of Thailand ; Special Task Force for Activating Research ; National Science and Technology Development Agency of Thailand ; Scientific and Technical Research Council of Turkey ; Turkish Atomic Energy Authority ; National Academy of Sciences of Ukraine ; State Fund for Fundamental Researches, Ukraine ; Science and Technology Facilities Council, United Kingdom ; U.S. Department of Energy ; U.S. National Science Foundation ; Marie-Curie program (European Union) ; European Research Council (European Union) ; 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 program of the Foundation for Polish Science, European Union ; Regional Development Fund ; Mobility Plus program of the Ministry of Science and Higher Education ; National Science Center (Poland) ; Sonata-bis ; Thalis and Aristeia programs - EU-ESF ; Greek NSRF ; National Priorities Research Program by Qatar National Research Fund ; Programa Clarin-COFUND del Principado de Asturias ; Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkom University ; Chulalongkom Academic into its 2nd Century Project Advancement Project (Thailand) ; Welch Foundation ; Ministry of Education and Research, Estonian Research Council: IUT23-4 ; Ministry of Education and Research, Estonian Research Council: IUT23-6 ; National Science Center (Poland): Harmonia 2014/14/M/ST2/00428 ; National Science Center (Poland): Opus 2013/11/B/ST2/04202 ; National Science Center (Poland): 2014/13/B/ST2/02543 ; National Science Center (Poland): 2014/15/B/ST2/03998 ; Sonata-bis: 2012/07/E/ST2/01406 ; Welch Foundation: C-1845 ; Differential and double-differential cross sections for the production of top quark pairs in proton-proton collisions at 13 TeV are measured as a function of jet multiplicity and of kinematic variables of the top quarks and the top quark-antiquark system. This analysis is based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 2.3 fb(-1). The measurements are performed in the lepton + jets decay channels with a single muon or electron in the final state. The differential cross sections are presented at particle level, within a phase space close to the experimental acceptance, and at parton level in the full phase space. The results are compared to several standard model predictions.