Search for heavy Majorana neutrinos in same-sign dilepton channels in proton-proton collisions at root s = TeV
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) ; Brazilian Funding Agency (FAPERGS) ; 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, Estonia ; Estonian Research Council, Estonia ; 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, France ; Commissariat a l'Energie Atomique et aux Energies Alternatives/CEA, France ; Bundesministerium fur Bildung und Forschung, Germany ; Deutsche Forschungsgemeinschaft, Germany ; Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany ; General Secretariat for Research and Technology, Greece ; National Research, Development and Innovation Fund, Hungary ; Department of Atomic Energy, India ; 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, Republic of Korea ; National Research Foundation (NRF), Republic of Korea ; Lithuanian Academy of Sciences ; Ministry of Education (Malaysia) ; University of Malaya (Malaysia) ; Ministry of Science of Montenegro ; 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, Poland ; National Science Center, Poland ; Fundacao 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 ; National Research Center Kurchatov Institute ; Ministry of Education, Science and Technological Development of Serbia ; Secretaria de Estado de Investigacion, Desarrollo e Innovacion, Programa Consolider-Ingenio 2010, Spain ; Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion 2013-2016, Spain ; Plan de Ciencia, Tecnologia e Innovacion 2013-2017 del Principado de Asturias, Spain ; Fondo Europeo de Desarrollo Regional, Spain ; Ministry of Science, Technology and Research, Sri Lanka ; 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, Ukraine ; State Fund for Fundamental Researches, Ukraine ; Science and Technology Facilities Council, U.K. ; U.S. Department of Energy ; U.S. National Science Foundation ; Marie-Curie program (European Union) ; European Research Council and Horizon 2020 Grant (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) ; F.R.S.-FNRS (Belgium) under the Excellence of Science - EOS - be.h project ; FWO (Belgium) under the Excellence of Science - EOS - be.h project ; Ministry of Education, Youth and Sports (MEYS) of the Czech Republic ; Lendulet (Momentum) Program (Hungary) ; Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences (Hungary) ; New National Excellence Program UNKP (Hungary) ; NKFIA (Hungary) ; Council of Scientific and Industrial Research, India ; HOMING PLUS program of the Foundation for Polish Science ; European Union, Regional Development Fund (Poland) ; Mobility Plus program of the Ministry of Science and Higher Education (Poland) ; National Science Center (Poland) ; National Priorities Research Program by Qatar National Research Fund ; Programa de Excelencia Maria de Maeztu ; Programa Severo Ochoa del Principado de Asturias ; Thalis program - EU-ESF ; Aristeia program - EU-ESF ; Greek NSRF ; Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand) ; Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand) ; Welch Foundation ; Weston Havens Foundation (U.S.A.) ; Estonian Research Council, Estonia: IUT23-4 ; Estonian Research Council, Estonia: IUT23-6 ; European Research Council and Horizon 2020 Grant (European Union): 675440 ; F.R.S.-FNRS (Belgium) under the Excellence of Science - EOS - be.h project: 30820817 ; FWO (Belgium) under the Excellence of Science - EOS - be.h project: 30820817 ; NKFIA (Hungary): 123842 ; NKFIA (Hungary): 123959 ; NKFIA (Hungary): 124845 ; NKFIA (Hungary): 124850 ; NKFIA (Hungary): 125105 ; European Union, Regional Development Fund (Poland): Harmonia 2014/14/M/ST2/00428 ; European Union, Regional Development Fund (Poland): Opus 2014/13/B/ST2/02543 ; European Union, Regional Development Fund (Poland): 2014/15/B/ST2/03998 ; European Union, Regional Development Fund (Poland): 2015/19/B/ST2/02861 ; European Union, Regional Development Fund (Poland): Sonata-bis 2012/07/E/ST2/01406 ; Mobility Plus program of the Ministry of Science and Higher Education (Poland): Harmonia 2014/14/M/ST2/00428 ; Mobility Plus program of the Ministry of Science and Higher Education (Poland): Opus 2014/13/B/ST2/02543 ; Mobility Plus program of the Ministry of Science and Higher Education (Poland): 2014/15/B/ST2/03998 ; Mobility Plus program of the Ministry of Science and Higher Education (Poland): 2015/19/B/ST2/02861 ; Mobility Plus program of the Ministry of Science and Higher Education (Poland): Sonata-bis 2012/07/E/ST2/01406 ; National Science Center (Poland): Harmonia 2014/14/M/ST2/00428 ; National Science Center (Poland): Opus 2014/13/B/ST2/02543 ; National Science Center (Poland): 2014/15/B/ST2/03998 ; National Science Center (Poland): 2015/19/B/ST2/02861 ; National Science Center (Poland): Sonata-bis 2012/07/E/ST2/01406 ; Welch Foundation: C-1845 ; A search is performed for a heavy Majorana neutrino (N), produced in leptonic decay of a W boson propagator and decaying into a W boson and a lepton, with the CMS detector at the LHC. The signature used in this search consists of two same-sign leptons, in any flavor combination of electrons and muons, and at least one jet. The data were collected during 2016 in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). The results are found to be consistent with the expected standard model background. Upper limits are set in the mass range between 20 and 1600 GeV in the context of a Type-I seesaw mechanism, on |V-eN|(2), |V-N|(2), and |VeNV *|(2)/(|V-eN|(2)+|V-N|(2)), where V-N is the matrix element describing the mixing of N with the standard model neutrino of flavor = e, . For N masses between 20 and 1600 GeV, the upper limits on |V-N|(2) range between 2.3 x 10(-5) and unity. These are the most restrictive direct limits for heavy Majorana neutrino masses above 430 GeV.