Abstract
Results are presented from a search for supersymmetric particles in scenarios with small mass splittings. The data sample corresponds to 19.7 fb−1 of proton–proton collisions recorded by the CMS experiment at s=8 TeV. The search targets top squark (t˜) pair production in scenarios with mass differences Δm=m(t˜)−m(χ˜1 0) below the W-boson mass and with top-squark decays in the four-body mode (t˜→bℓνχ˜1 0), where the neutralino (χ˜1 0) is assumed to be the lightest supersymmetric particle (LSP). The signature includes a high transverse momentum (pT) jet associated with initial-state radiation, one or two low-pT leptons, and significant missing transverse energy. The event yields observed in data are consistent with the expected background contributions from standard model processes. Limits are set on the cross section for top squark pair production as a function of the t˜ and LSP masses. Assuming a 100% branching fraction for the four-body decay mode, top-squark masses below 316 GeV are excluded for Δm=25 GeV at 95% CL. The dilepton data are also interpreted under the assumption of chargino–neutralino production, with subsequent decays to sleptons or sneutrinos. Assuming a difference between the common χ˜1 +/χ˜2 0 mass and the LSP mass of 20 GeV and a τ-enriched decay scenario, masses in the range m(χ˜1 +)<307 GeV are excluded at 95% CL.
Original language | English |
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Pages (from-to) | 9-35 |
Number of pages | 27 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 759 |
DOIs | |
Publication status | Published - 10 Aug 2016 |
Bibliographical note
Publisher Copyright:© 2016 The Author
Funding
Individuals have received support from the Marie-Curie programme and the European Research Council and EPLANET (European Union); the Leventis Foundation ; the Alfred 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 programme of the Foundation for Polish Science , cofinanced from European Union, Regional Development Fund ; the OPUS programme of the National Science Center (Poland); the Compagnia di San Paolo (Torino); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF ; the National Priorities Research Program by Qatar National Research Fund ; the Rachadapisek Sompot Fund for Postdoctoral Fellowship , Chulalongkorn University (Thailand); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation , contract C-1845 . 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); 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); and DOE and NSF (USA). Individuals have received support from the Marie-Curie programme and the European Research Council and EPLANET (European Union); the Leventis Foundation; the Alfred 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 programme of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the OPUS programme of the National Science Center (Poland); the Compagnia di San Paolo (Torino); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; the National Priorities Research Program by Qatar National Research Fund; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation, contract C-1845.
Funders | Funder number |
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CPAN | |
Chulalongkorn Academic | |
EU-ESF | |
MSES | |
MoER | |
STAR | |
National Science Foundation | 1206044, 1314131, 1306951, 1506130, 1120138, 1211067 |
National Institutes of Health | |
U.S. Department of Energy | |
Alfred P. Sloan Foundation | |
Welch Foundation | C-1845 |
Hispanics in Philanthropy | |
Human Growth Foundation | |
Alexander von Humboldt-Stiftung | |
California Department of Fish and Wildlife | |
Ministry of Science and Technology | |
University of Minnesota | |
Compagnia di San Paolo | |
Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) | |
Children's Specialists Foundation | |
California Earthquake Authority | |
Qatar National Research Fund | |
Direktion für Entwicklung und Zusammenarbeit | |
Ministry of Education | |
Center for African Studies | |
Secretaría de Educación Pública | |
Türkiye Atom Enerjisi Kurumu | |
Seventh Framework Programme | 246806 |
Santa Fe Institute | |
Louisiana Academy of Sciences | |
Rochester Academy of Science | |
National Research Foundation | |
Missouri University of Science and Technology | |
Medical Engineering Centre, King’s College London | |
CERN | |
Thailand Center of Excellence in Physics | |
Cosmetic Surgery Foundation | |
Institute for the Promotion of Teaching Science and Technology | |
Ministerstwo Obrony Narodowej | |
Science and Technology Facilities Council | ST/N000250/1, ST/K003542/1, ST/K001256/1, ST/J004871/1, GRIDPP, PP/E002803/1, ST/N001273/1, ST/H000925/2, ST/H000925/1, ST/J005479/1, ST/K001531/1, ST/I000305/1, PP/E000479/1, ST/M004775/1, ST/K001639/1, ST/L005603/1, ST/M002020/1, ST/I003622/1, ST/N000242/1 |
European Commission | |
European Research Council | |
National Stroke Foundation | |
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 | |
Eesti Teadusagentuur | |
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 | |
Chulalongkorn University | |
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 Educación, Cultura y Deporte | |
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 | |
Ministry of Science ICT and Future Planning | |
A.G. Leventis Foundation | |
National Science and Technology Development Agency | |
Narodowe Centrum Nauki | |
Universiti Malaya | |
Türkiye Bilimsel ve Teknolojik Araştirma Kurumu | |
Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja | |
Ministerstwo Edukacji i Nauki | |
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 | |
Universidad Autónoma de San Luis Potosí | |
Ministry of Education and Science | |
Institute for Research in Fundamental Sciences | |
Commissariat à l'Énergie Atomique et aux Énergies Alternatives | |
Bundesministerium für Bildung und Frauen | |
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 | |
Department of Science and Technology, Government of West Bengal | |
Fundació Catalana de Trasplantament | |
Institut National de Physique Nucléaire et de Physique des Particules |
Keywords
- CMS
- Physics
- Supersymmetry