Search for top quark partners with charge 5/3 in the same-sign dilepton and single-lepton final states in proton-proton collisions at √s =13 TeV
A search for the pair production of heavy fermionic partners of the top quark with charge 5/3 (X 5/3 ) is performed in proton-proton collisions at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. The data sample analyzed corresponds to an integrated luminosity of 35.9 fb ?1 . The X 5/3 quark is assumed always to decay into a top quark and a W boson. Both the right-handed and left-handed X 5/3 couplings to the W boson are considered. Final states with either a pair of same-sign leptons or a single lepton are studied. No significant excess of events is observed above the expected standard model background. Lower limits at 95% confidence level on the X 5/3 quark mass are set at 1.33 and 1.30 TeV respectively for the case of right-handed and left-handed couplings to W bosons in a combination of the same-sign dilepton and single-lepton final states.[Figure not available: see fulltext.] © 2019, The Author(s). ; California Earthquake Authority, CEA Secretaría de Educación Superior, Ciencia, Tecnología e Innovación, SENESCYT Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, FAPERJ State Fund for Fundamental Research of Ukraine, SFFR CS Fund, CSF Fundação para a Ciência e a Tecnologia, FCT Joint Institute for Nuclear Research, JINR Ministry of Education - Singapore, MOE Pakistan Atomic Energy Commission, PAEC Consejo Nacional de Ciencia y Tecnología, CONACYT National Science and Technology Development Agency, ????: Thailand Ministry for Business Innovation and Employment, MBIE Institute for Research in Fundamental Sciences, IPM Ministry of Science and Technology, MOST Missouri University of Science and Technology, MST Benemérita Universidad Autónoma de Puebla, BUAP Hispanics in Philanthropy, HIP European Regional Development Fund, FEDER Deutsche Forschungsgemeinschaft, DFG National Research Foundation of Korea, NRF Secretaría de Estado de Investigación, Desarrollo e Innovación, SEIDI Ministry of Science, ICT and Future Planning, MSIP U.S. Department of Energy, USDOE Academy of Finland Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES Norwegian Sequencing Centre, NSC Türkiye Atom Enerjisi Kurumu, TAEK Mountain Equipment Co-operative, MEC Research Promotion Foundation, ???? National Science Foundation, NSF Science and Technology Facilities Council, STFC Helmholtz-Gemeinschaft, HGF Austrian Science Fund, FWF Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP Secretaría de Educación Pública, SEP Bundesministerium für Wissenschaft, Forschung und Wirtschaft, BMWFW Fonds De La Recherche Scientifique - FNRS, FNRS National Academy of Sciences of Ukraine, NASU Bundesministerium für Bildung und Forschung, BMBF National Natural Science Foundation of China, NSFC Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CINVESTAV Instituto Nazionale di Fisica Nucleare, INFN Department of Atomic Energy, Government of India, ???? Universiti Malaya, UM Royal Astronomical Society, RAS Department of Science and Technology, Government of West Bengal, DST State Atomic Energy Corporation ROSATOM, ROSATOM Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq Russian Foundation for Basic Research, ???? College of Arts and Sciences, University of Nebraska-Lincoln, CAS European Regional Development Fund, FEDER CERN General Secretariat for Research and Technology, GSRT Fonds Wetenschappelijk Onderzoek, FWO Science Foundation Ireland, SFI Ministry of Education and Science, MES Louisiana Academy of Sciences, LAS Institute for the Promotion of Teaching Science and Technology, IPST Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA European Research Council, ERC Horizon 2020: 675440 European Commission, EC A.G. Leventis Foundation American Friends of the Alexander von Humboldt Foundation, AFAvH European Regional Development Fund, FEDER Welch Foundation: C-1845 Weston Havens Foundation Fundacja na rzecz Nauki Polskiej, FNP Comisión Asesora de Investigación Científica y Técnica, CAICYT: MDM-2015-0509 Qatar National Research Fund, QNRF Agentschap voor Innovatie door Wetenschap en Technologie, IWT Belgian Federal Science Policy Office, BELSPO Chulalongkorn University, CU Ministerstvo Školství, Mláde?e a T?lov?chovy, MŠMT European Commission, EC Ministerstvo Školství, Mláde?e a T?lov?chovy, MŠMT 30820817 2012/07/E/ST2/01406, 2014/13/B/ST2/02543, 2014/14/M/ST2/00428, 2014/15/B/ST2/03998, 2015/19/B/ST2/02861 Fonds Wetenschappelijk Onderzoek, FWO Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture, FRIA Magyar Tudományos Akadémia, MTA Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA: 125105, 124850, 123842, 123959, 124845 ; Open Access, Copyright CERN, for the benefit of the CMS Collaboration. Article funded by SCOAP3. ; We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centres and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMWFW and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COL-CIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador); MoER, ERC IUT, and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI and FEDER (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (U.S.A.). ; Individuals have received support from the Marie-Curie programme and the European Research Council and Horizon 2020 Grant, contract No. 675440 (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Founda- ; tion; 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 F.R.S.-FNRS and FWO (Belgium) under the "Excellence of Science — EOS" — be.h project n. 30820817; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lendület ("Momentum") Programme and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program ÚNKP, the NKFIA research grants 123842, 123959, 124845, 124850 and 125105 (Hungary); the Council of Science and Industrial Research, India; the HOMING PLUS programme of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus programme 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 Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programmes 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); the Welch Foundation, contract C-1845; and the Weston Havens Foundation (U.S.A.).