Search for top-squark pair production in the single-lepton final state in pp collisions at
BMWF (Austria) ; FWF (Austria) ; FNRS (Belgium) ; FWO (Belgium) ; 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) ; MEYS (Bulgaria) ; CERN ; CAS (China) ; MoST (China) ; NSFC (China) ; COLCIENCIAS (Colombia) ; MSES (Croatia) ; RPF (Cyprus) ; MoER (Estonia) ; ERDF (Estonia) ; Academy of Finland (Finland) ; MEC (Finland) ; HIP (Finland) ; CEA (France) ; CNRS/IN2P3 (France) ; BMBF (Germany) ; DFG (Germany) ; HGF (Germany) ; GSRT (Greece) ; OTKA (Hungary) ; NKTH (Hungary) ; DAE (India) ; DST (India) ; IPM (Iran) ; SFI (Ireland) ; INFN (Italy) ; NRF (Republic of Korea) ; WCU (Republic of Korea) ; LAS (Lithuania) ; CINVESTAV (Mexico) ; CONACYT (Mexico) ; SEP (Mexico) ; UASLP-FAI (Mexico) ; MSI (New Zealand) ; PAEC (Pakistan) ; MSHE (Poland) ; NSC (Poland) ; FCT (Portugal) ; JINR (Armenia) ; JINR (Belarus) ; JINR (Georgia) ; JINR (Ukraine) ; JINR (Uzbekistan) ; MON (Russia) ; RosAtom (Russia) ; RAS (Russia) ; RFBR (Russia) ; MSTD (Serbia) ; SEIDI (Spain) ; CPAN (Spain) ; Swiss Funding Agencies (Switzerland) ; NSC (Taipei) ; ThEPCenter (Thailand) ; IPST (Thailand) ; NSTDA (Thailand) ; TUBITAK (Turkey) ; TAEK (Turkey) ; NASU (Ukraine) ; STFC (United Kingdom) ; DOE (USA) ; NSF (USA) ; University of California Institute for Mexico and the United States ; 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 Czech Republic ; Agence Nationale de la Recherche (France) ; Council of Science and Industrial Research, India ; Compagnia di San Paolo (Torino) ; HOMING PLUS programme of Foundation for Polish Science ; EU, Regional Development Fund ; Thalis programme ; Aristeia programme ; EU-ESF ; Greek NSRF ; MoER (Estonia)SF0690030s09 ; Agence Nationale de la Recherche (France)ANR-12-JS05-002-01 ; This paper presents a search for the pair production of top squarks in events with a single isolated electron or muon, jets, large missing transverse momentum, and large transverse mass. The data sample corresponds to an integrated luminosity of 19.5 fb(-1) of pp collisions collected in 2012 by the CMS experiment at the LHC at a center-of-mass energy of . No significant excess in data is observed above the expectation from standard model processes. The results are interpreted in the context of supersymmetric models with pair production of top squarks that decay either to a top quark and a neutralino or to a bottom quark and a chargino. For small mass values of the lightest supersymmetric particle, top-squark mass values up to around 650 GeV are excluded.