Abstract
A search has been performed for long-lived particles that could have come to rest within the CMS detector, using the time intervals between LHC beam crossings. The existence of such particles could be deduced from observation of their decays via energy deposits in the CMS calorimeter appearing at times that are well separated from any proton–proton collisions. Using a data set corresponding to an integrated luminosity of 18.6-1 of 8 TeV proton–proton collisions, and a search interval corresponding to 281 h of trigger livetime, 10 events are observed, with a background prediction of 132-2.5 +3.6 events. Limits are presented at 95 % confidence level on gluino and top squark production, for over 13 orders of magnitude in the mean proper lifetime of the stopped particle. Assuming a cloud model of R-hadron interactions, a gluino with mass ≲1000 GeV and a top squark with mass ≲525 GeV are excluded, for lifetimes between 1 μs and 1000s. These results are the most stringent constraints on stopped particles to date.
Original language | English |
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Article number | 151 |
Pages (from-to) | 1-22 |
Number of pages | 22 |
Journal | European Physical Journal C |
Volume | 75 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Apr 2015 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2015, CERN for the benefit of the CMS collaboration.
Funding
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 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 Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the Compagnia di San Paolo (Torino); the Consorzio per la Fisica (Trieste); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund.
Funders | Funder number |
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CPAN | |
Consorzio per la Fisica | |
ERC IUT | |
EU-ESF | |
FRIA-Belgium | |
IWT-Belgium | |
MESTD | |
MON | |
MSES | |
MSHE | |
MoER | |
STAR | |
Swiss Funding Agencies | |
TUBITAK | |
UASLP-FAI | |
National Science Foundation | 1151640, 1206044, 1314131, 1306951, 1205960, 1120138, 1211067 |
National Institutes of Health | |
U.S. Department of Energy | |
Alfred P. Sloan Foundation | |
Hispanics in Philanthropy | |
Alexander von Humboldt-Stiftung | |
Compagnia di San Paolo | |
Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) | |
Qatar National Research Fund | |
Secretaría de Educación Pública | |
Türkiye Atom Enerjisi Kurumu | |
Louisiana Academy of Sciences | |
Missouri University of Science and Technology | |
CERN | |
Thailand Center of Excellence in Physics | |
Cosmetic Surgery Foundation | |
Institute for the Promotion of Teaching Science and Technology | |
Science and Technology Facilities Council | ST/L00609X/1, ST/N000250/1, ST/J004901/1, ST/K003542/1, ST/K001256/1, ST/K003844/1, CMS, GRIDPP, ST/M005356/1, ST/I505580/1, ST/I005912/1, ST/J005665/1, ST/J50094X/1, ST/K001604/1, ST/M004775/1, ST/K001639/1, ST/L005603/1 |
European Commission | |
European Research Council | |
Department of Science and Technology, Ministry of Science and Technology, India | |
Council of Scientific and Industrial Research, India | |
Ministry of Education - Singapore | |
Department of Atomic Energy, Government of India | |
Science Foundation Ireland | |
Helmholtz-Gemeinschaft | |
Deutsche Forschungsgemeinschaft | |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 153664 |
Fundação de Amparo à Pesquisa do Estado de São Paulo | |
National Natural Science Foundation of China | |
Research Promotion Foundation | |
Ministerstvo Školství, Mládeže a Tělovýchovy | |
National Science Council | |
Fundacja na rzecz Nauki Polskiej | |
Fundação para a Ciência e a Tecnologia | |
Russian Foundation for Basic Research | |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |
Academy of Finland | |
Bundesministerium für Bildung und Forschung | |
Chinese Academy of Sciences | |
Austrian Science Fund | |
Fonds De La Recherche Scientifique - FNRS | |
Russian Academy of Sciences | |
Belgian Federal Science Policy Office | |
Fonds Wetenschappelijk Onderzoek | |
Agentschap voor Innovatie door Wetenschap en Technologie | |
Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture | |
Consejo Nacional de Ciencia y Tecnología | |
Ministerio de Economía y Competitividad | |
Ministero dell’Istruzione, dell’Università e della Ricerca | 20108T4XTM |
Bundesministerium für Wissenschaft, Forschung und Wirtschaft | |
General Secretariat for Research and Technology | |
Ministry of Business, Innovation and Employment | |
Hungarian Scientific Research Fund | |
Conselho Nacional de Desenvolvimento Científico e Tecnológico | |
Ministry of Science, ICT and Future Planning | |
National Research Foundation of Korea | |
Joint Institute for Nuclear Research | |
Instituto Nazionale di Fisica Nucleare | |
A.G. Leventis Foundation | |
National Science and Technology Development Agency | |
Universiti Malaya | |
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro | |
Ministry of Science and Technology, Taiwan | |
National Academy of Sciences of Ukraine | |
Centre National de la Recherche Scientifique | |
Ministry of Education and Science | |
Institute for Research in Fundamental Sciences | |
Commissariat à l'Énergie Atomique et aux Énergies Alternatives | |
Secretaría de Estado de Investigación, Desarrollo e Innovación | |
European Regional Development Fund | |
State Atomic Energy Corporation ROSATOM | |
Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional | |
Pakistan Atomic Energy Commission | |
State Fund for Fundamental Research of Ukraine | |
Institut National de Physique Nucléaire et de Physique des Particules |