Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at root s=8Tev

Abstract

WOS: 000352154400001 ; A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a displaced secondary vertex. Events corresponding to an integrated luminosity of 19.6 (20.5) fb(-1) in the electron (muon) channel were collected with the CMS detector at the CERN LHC in proton-proton collisions at root s TeV. No significant excess is observed above standard model expectations. Upper limits on the product of the cross section and branching fraction of such a signal are presented as a function of the long-lived particle's mean proper decay length. The limits are presented in an approximately model-independent way, allowing them to be applied to a wide class of models yielding the above topology. Over much of the investigated parameter space, the limits obtained are the most stringent to date. In the specific case of a model in which a Higgs boson in the mass range 125-1000 GeV/c(2) decays into a pair of long-lived neutral bosons in the mass range 20-350 GeV= c(2), each of which can then decay to dileptons, the upper limits obtained are typically in the range 0.2-10 fb for mean proper decay lengths of the long-lived particles in the range 0.01-100 cm. In the case of the lowest Higgs mass considered (125 GeV/c(2)), the limits are in the range 2-50 fb. These limits are sensitive to Higgs boson branching fractions as low as 10(-1). ; BMWFW (Austria); FWF (Austria)Austrian Science Fund (FWF); FNRS (Belgium)Fonds de la Recherche Scientifique - FNRS; FWO (Belgium)FWO; CNPq (Brazil)National Council for Scientific and Technological Development (CNPq); CAPES (Brazil)CAPES; FAPERJ (Brazil)Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ); FAPESP (Brazil)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); MES (Bulgaria); CERN; CAS (China)Chinese Academy of Sciences; MoST (China)Ministry of Science and Technology, China; NSFC (China)National Natural Science Foundation of China; COLCIENCIAS (Colombia)Departamento Administrativo de Ciencia, Tecnologia e Innovacion Colciencias; MSES (Croatia); CSF (Croatia); RPF (Cyprus); MoER (Estonia); ERC IUT (Estonia)Estonian Research Council; ERDF (Estonia)European Union (EU); Academy of Finland (Finland)Academy of Finland; MEC (Finland)Spanish Government; HIP (Finland); CEA (France)French Atomic Energy Commission; CNRS/IN2P3 (France)Centre National de la Recherche Scientifique (CNRS); BMBF (Germany)Federal Ministry of Education & Research (BMBF); DFG (Germany)German Research Foundation (DFG); HGF (Germany); GSRT (Greece)Greek Ministry of Development-GSRT; OTKA (Hungary)Orszagos Tudomanyos Kutatasi Alapprogramok (OTKA); NIH (Hungary)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA; DAE (India)Department of Atomic Energy (DAE); DST (India)Department of Science & Technology (India); IPM (Iran); SFI (Ireland)Science Foundation Ireland; INFN (Italy)Istituto Nazionale di Fisica Nucleare (INFN); MSIP (Republic of Korea); NRF (Republic of Korea); LAS (Lithuania); MOE (Malaysia); UM (Malaysia); CINVESTAV (Mexico); CONACYT (Mexico)Consejo Nacional de Ciencia y Tecnologia (CONACyT); SEP (Mexico); UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE (Poland); NSC (Poland); FCT (Portugal)Portuguese Foundation for Science and Technology; JINR (Dubna); MON (Russia); RosAtom (Russia); RAS (Russia)Russian Academy of Sciences; RFBR (Russia)Russian Foundation for Basic Research (RFBR); MESTD (Serbia); SEIDI (Spain); CPAN (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter (Thailand); IPST (Thailand); STAR (Thailand); NSTDA (Thailand); TUBITAK (Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); TAEK (Turkey)Ministry of Energy & Natural Resources - Turkey; NASU (Ukraine); SFFR (Ukraine)State Fund for Fundamental Research (SFFR); STFC (United Kingdom)Science & Technology Facilities Council (STFC); DOE (USA)United States Department of Energy (DOE); NSF (USA)National Science Foundation (NSF); Marie Curie program (European Union)European Union (EU); European Research Council (European Union)European Union (EU)European Research Council (ERC); EPLANET (European Union)European Union (EU); Leventis Foundation; A. P. Sloan FoundationAlfred P. Sloan Foundation; Alexander von Humboldt FoundationAlexander von Humboldt Foundation; Belgian Federal Science Policy OfficeBelgian Federal Science Policy Office; Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA Belgium)Fonds de la Recherche Scientifique - FNRS; Agentschap voor Innovatie door Wetenschap en Technologie (IWT Belgium)Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT); Ministry of Education, Youth and Sports (MEYS) of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic; Council of Science and Industrial Research, IndiaCouncil of Scientific & Industrial Research (CSIR) - India; HOMING PLUS program of Foundation for Polish Science; European Union, Regional Development FundEuropean Union (EU); Compagnia di San Paolo (Torino)Compagnia di San Paolo; Consorzio per la Fisica (Trieste); MIUR (Italy)Ministry of Education, Universities and Research (MIUR) [20108T4XTM]; Thalis programme; Aristeia programme; EU-ESFEuropean Union (EU); Greek NSRFGreek Ministry of Development-GSRT; National Priorities Research Program by Qatar National Research Fund; Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC) [ST/K001256/1, ST/L005603/1, ST/M005356/1 GRIDPP, ST/L00609X/1, ST/M005356/1, GRIDPP, ST/K003542/1, ST/K003844/1, ST/I005912/1, ST/I505580/1, ST/K003844/1 GRIDPP, ST/J005665/1, CMS, ST/L00609X/1 GRIDPP, ST/I005912/1 GRIDPP, ST/K001639/1, ST/J004901/1, ST/K001604/1, ST/N000250/1, ST/J50094X/1, ST/M004775/1] ; 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 centers 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); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); 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); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); CINVESTAV, CONACYT, 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 and CPAN (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 (USA). 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 a 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 Foundation for Polish Science, cofinanced by the European Union, Regional Development Fund; the Compagnia di San Paolo (Torino); the Consorzio per la Fisica (Trieste); MIUR Grant No. 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund.