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Observation of the Z → ψℓ^+ℓ^− Decay in pp Collisions at √s = 13  TeV

Sirunyan, A. M. and Anderson, D. and Bornheim, A. and Lawhorn, J. M. and Newman, H. B. and Nguyen, T. Q. and Spiropulu, M. and Vlimant, J. R. and Wilkinson, R. and Xie, S. and Zhang, Z. and Zhu, R. Y. and Dubinin, M. (2018) Observation of the Z → ψℓ^+ℓ^− Decay in pp Collisions at √s = 13  TeV. Physical Review Letters, 121 (14). Art. No. 141801. ISSN 0031-9007. http://resolver.caltech.edu/CaltechAUTHORS:20181024-144229381

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Abstract

This Letter presents the observation of the rare Z boson decay Z → ψℓ^+ℓ^−. Here, ψ represents contributions from direct J/ψ and ψ(2S)→J/ψX, ℓ^+ℓ^− is a pair of electrons or muons, and the J/ψ meson is detected via its decay to μ^+μ^−. The sample of proton-proton collision data, collected by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, corresponds to an integrated luminosity of 35.9  fb−1. The signal is observed with a significance in excess of 5 standard deviations. After subtraction of the ψ(2S) → J/ψX contribution, the ratio of the branching fraction of the exclusive decay Z→J/ψℓ+ℓ− to the decay Z → μ^+μ^−μ^+μ^− within a fiducial phase space is measured to be B(Z → J/ψℓ^+ℓ^−)/B(Z → μ^+μ^−μ^+μ^−) = 0.67 ± 0.18(stat) ± 0.05(syst).


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1103/PhysRevLett.121.141801DOIArticle
https://arxiv.org/abs/1806.04213arXivDiscussion Paper
ORCID:
AuthorORCID
Newman, H. B.0000-0003-0964-1480
Nguyen, T. Q.0000-0003-3954-5131
Spiropulu, M.0000-0001-8172-7081
Xie, S.0000-0003-2509-5731
Zhang, Z.0000-0002-1630-0986
Zhu, R. Y.0000-0003-3091-7461
Additional Information:© 2018 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3. Received 11 June 2018; published 4 October 2018. 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: BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (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); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR, and NRC KI (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 (USA).
Group:CMS@Caltech
Funders:
Funding AgencyGrant Number
Bundesministerium für Wissenschaft, Forschung Und Wirtschaft (BMWFW)UNSPECIFIED
FWF Der WissenschaftsfondsUNSPECIFIED
Fonds de la Recherche Scientifique (FNRS)UNSPECIFIED
Fonds Wetenschappelijk Onderzoek (FWO)UNSPECIFIED
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNSPECIFIED
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNSPECIFIED
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)UNSPECIFIED
Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS)UNSPECIFIED
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UNSPECIFIED
Ministry of Education and Science (Bulgaria)UNSPECIFIED
CERNUNSPECIFIED
Chinese Academy of SciencesUNSPECIFIED
Ministry of Science and Technology (China)UNSPECIFIED
National Natural Science Foundation of ChinaUNSPECIFIED
Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS)UNSPECIFIED
Ministry of Science, Education and Sport (Croatia)UNSPECIFIED
Croatian Science FoundationUNSPECIFIED
Research Promotion Foundation (Cyprus)UNSPECIFIED
Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT)UNSPECIFIED
Ministry of Education and Research (Estonia)UNSPECIFIED
Estonian Research CouncilUNSPECIFIED
European Regional Development Fund (Estonia)UNSPECIFIED
Academy of FinlandUNSPECIFIED
Ministry of Education and Culture (Finland)UNSPECIFIED
Helsinki Institute of PhysicsUNSPECIFIED
Commissariat a l'Energie Atomique (CEA)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)UNSPECIFIED
Bundesministerium für Bildung und Forschung (BMBF)UNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)UNSPECIFIED
Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)UNSPECIFIED
General Secretariat for Research and Technology (GSRT)UNSPECIFIED
National Research, Development and Innovation Office (Hungary)UNSPECIFIED
Department of Atomic Energy (India)UNSPECIFIED
Department of Science and Technology (India)UNSPECIFIED
Institute for Studies in Theoretical Physics and Mathematics (Iran)UNSPECIFIED
Science Foundation, IrelandUNSPECIFIED
Istituto Nazionale di Fisica Nucleare (INFN)UNSPECIFIED
Ministry of Science, ICT and Future Planning (Korea)UNSPECIFIED
National Research Foundation of KoreaUNSPECIFIED
Lithuanian Academy of SciencesUNSPECIFIED
Ministry of Education (Malaysia)UNSPECIFIED
University of MalayaUNSPECIFIED
Benemérita Universidad Autónoma de Puebla (BUAP)UNSPECIFIED
Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV)UNSPECIFIED
Consejo Nacional de Ciencia y Tecnología (CONACYT)UNSPECIFIED
Laboratorio Nacional de Supercómputo (LNS)UNSPECIFIED
Secretaría de Educación Pública (SEP)UNSPECIFIED
Ministero della Scienza del Montenegro (MOS)UNSPECIFIED
Universidad Autónoma de San Luis Potosí Inicio-Facultad de Ingeniería (UASLP-FAI)UNSPECIFIED
Ministry of Business, Innovation and Employment (New Zealand)UNSPECIFIED
Atomic Energy Commission (Pakistan)UNSPECIFIED
Ministry of Science and Higher Education (Poland)UNSPECIFIED
National Science Centre (Poland)UNSPECIFIED
Fundação para a Ciência e Tecnologia (FCT)UNSPECIFIED
Joint Institute for Nuclear Research (JINR)UNSPECIFIED
Russian Ministry of Education and Sciences (MON)UNSPECIFIED
RosAtomUNSPECIFIED
Russian Academy of SciencesUNSPECIFIED
Russian Foundation for Basic ResearchUNSPECIFIED
Russian Academic Excellence Project (RAEP)UNSPECIFIED
National Research Center, Kurchatov Institute (Russia)UNSPECIFIED
Ministry of Education, Science and Technological Development (Serbia)UNSPECIFIED
Secretaría de Estado de Investigación, Desarrollo e Innovación (SEIDI)UNSPECIFIED
Centro Nacional de Física de Partículas, Astropartículas y Nuclear (CPAN)UNSPECIFIED
Plan de Ciencia, Tecnología e Innovación (PCtI)UNSPECIFIED
Fondo Europeo de Desarrollo Regional (FEDER)UNSPECIFIED
Swiss Funding AgenciesUNSPECIFIED
Ministry of Science and Technology (Taipei)UNSPECIFIED
Thailand Center of Excellence in PhysicsUNSPECIFIED
Institute for the Promotion of Teaching Science and Technology (Thailand)UNSPECIFIED
Special Task Force for Activating Research (Thailand)UNSPECIFIED
National Science and Technology Development Agency (Thailand)UNSPECIFIED
Türkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK)UNSPECIFIED
Türkiye Atom Enerjisi Kurumu (TAEK)UNSPECIFIED
National Academy of Sciences (Ukraine)UNSPECIFIED
State Fund for Fundamental Research (Ukraine)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Department of Energy (DOE)UNSPECIFIED
NSFUNSPECIFIED
SCOAP3UNSPECIFIED
Record Number:CaltechAUTHORS:20181024-144229381
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20181024-144229381
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90403
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:25 Oct 2018 17:03
Last Modified:25 Oct 2018 17:03

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