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Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at √s = 8TeV

Khachatryan, V. and Apresyan, A. and Bornheim, A. and Bunn, J. and Chen, Y. and Di Marco, E. and Duarte, J. and Mott, A. and Newman, H. B. and Pena, C. and Rogan, C. and Spiropulu, M. and Timciuc, V. and Wilkinson, R. and Xie, S. and Zhu, R. Y. and Dubinin, M. (2014) Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at √s = 8TeV. European Physical Journal C, 74 (9). Art. No. 3060. ISSN 1434-6044. http://resolver.caltech.edu/CaltechAUTHORS:20150325-092903513

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Abstract

A measurement of the cross section for the production of top quark–antiquark pairs ( tt) in association with a vector boson V (W or Z) in proton-proton collisions at √s=8 TeV is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb^(−1) recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and μ) channels: a same-sign dilepton analysis targeting ttW events, and trilepton and four-lepton analyses designed for ttZ events. In the same-sign dilepton channel, the ttW cross section is measured as σtt¯W=170^(+90)_(−80)(stat)±70(syst)fb , corresponding to a significance of 1.6 standard deviations over the background-only hypothesis. Combining the trilepton and four-lepton channels, a direct measurement of the ttZ cross section, ttZ=200^(+80)_(−70)(stat)^(+40)_(−30)(syst)fb^(−1), is obtained with a significance of 3.1 standard deviations. The measured cross sections are compatible with standard model predictions within their experimental uncertainties. The inclusive ttV process is observed with a significance of 3.7 standard deviations from the combination of all three leptonic channels.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1140/epjc/s10052-014-3060-7DOIArticle
http://link.springer.com/article/10.1140/epjc/s10052-014-3060-7PublisherArticle
http://arxiv.org/abs/1406.7830arXivDiscussion Paper
Additional Information:© 2014 CERN for the benefit of the CMS collaboration 2014. This article is published with open access at Springerlink.com. Received: 30 June 2014. Accepted: 31 August 2014. Published online: 17 September 2014. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. Funded by SCOAP3. 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); NRF and WCU (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 programme 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 programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the Compagnia di San Paolo (Torino); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund.
Group:CMS@Caltech
Funders:
Funding AgencyGrant Number
SCOAP3UNSPECIFIED
BMWFW and FWF (Austria)UNSPECIFIED
FNRS and FWO (Belgium) UNSPECIFIED
CNPq, CAPES, FAPERJ, and FAPESP (Brazil)UNSPECIFIED
MES (Bulgaria)UNSPECIFIED
CERNUNSPECIFIED
CAS, MoST, and NSFC (China)UNSPECIFIED
COLCIENCIAS (Colombia)UNSPECIFIED
MSES and CSF (Croatia)UNSPECIFIED
RPF (Cyprus) UNSPECIFIED
MoER, ERC IUT, and ERDF (Estonia)UNSPECIFIED
Academy of Finland, MEC, and HIP (Finland)UNSPECIFIED
Commissariat à l’Énergie Atomique (CEA)UNSPECIFIED
Bundesministerium für Bildung und Forschung (BMBF)UNSPECIFIED
GSRT (Greece)UNSPECIFIED
OTKA and NIH (Hungary) UNSPECIFIED
DAE and DST (India) UNSPECIFIED
IPM (Iran)UNSPECIFIED
Science Foundation, IrelandUNSPECIFIED
Istituto Nazionale di Fisica Nucleare (INFN)UNSPECIFIED
NRF and WCU (Korea)UNSPECIFIED
LAS (Lithuania)UNSPECIFIED
MOE and UM (Malaysia)UNSPECIFIED
CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico)UNSPECIFIED
MBIE (New Zealand)UNSPECIFIED
PAEC (Pakistan)UNSPECIFIED
MSHE and NSC (Poland)UNSPECIFIED
Fundação para a Ciência e a Tecnologia (FCT)UNSPECIFIED
JINR (Dubna)UNSPECIFIED
MON, RosAtom, RAS, and RFBR (Russia)UNSPECIFIED
MESTD (Serbia)UNSPECIFIED
SEIDI and CPAN (Spain)UNSPECIFIED
Swiss Funding Agencies (Switzerland)UNSPECIFIED
MST (Tapei)UNSPECIFIED
ThEPCenter, IPST, STAR, and NSTDA (Thailand)UNSPECIFIED
TUBITAK and TAEK (Turkey) UNSPECIFIED
NASU and SFFR (Ukraine)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Department of Energy (DOE)UNSPECIFIED
NSFUNSPECIFIED
Marie-Curie programme and the European Research Council and EPLANET (European Union)UNSPECIFIED
Leventis Foundation UNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Alexander von Humboldt FoundationUNSPECIFIED
Belgian Federal Science Policy OfficeUNSPECIFIED
Fonds pour la Formation à la Recherche dans l’índustrie et dans l’Ágriculture (FRIA-Belgium)UNSPECIFIED
Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)UNSPECIFIED
Ministry of Education, Youth and Sports (MEYS) of the Czech RepublicUNSPECIFIED
Council of Science and Industrial Research, IndiaUNSPECIFIED
HOMING PLUS programme of Foundation for Polish Science cofinanced from European UnionUNSPECIFIED
Regional Development FundUNSPECIFIED
Compagnia di San Paolo (Torino)UNSPECIFIED
Thalis and Aristeia programmes cofinanced by EU-ESFUNSPECIFIED
Greek NSRFUNSPECIFIED
Qatar National Research Fund National Priorities Research ProgramUNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)UNSPECIFIED
Helmholtz-Gemeinschaft Deutscher Forschungszentren (Germany)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Record Number:CaltechAUTHORS:20150325-092903513
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20150325-092903513
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56063
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:25 Mar 2015 19:39
Last Modified:25 Mar 2015 19:39

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