Measurement of the top quark polarization and t(t)over-barspin correlations using dilepton final states in proton-proton collisions at root s=13 TeV

WOS:000489251000002Measurements of the top quark polarization and top quark pair (t (t) over bar) spin correlations are presented using events containing two oppositely charged leptons (e(+)e(-), e(+/-)mu(-/+), or mu(+)mu(-)) produced in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC in 2016 and correspond to an integrated luminosity of 35.9 fb(-1) . A set of parton-level normalized differential cross sections, sensitive to each of the independent coefficients of the spin-dependent parts of the t (t) over bar production density matrix, is measured for the first time at 13 TeV. The measured distributions and extracted coefficients are compared with standard model predictions from simulations at next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD), and from NLO QCD calculations including electroweak corrections. All measurements are found to be consistent with the expectations of the standard model. The normalized differential cross sections are used in fits to constrain the anomalous chromomagnetic and chromoelectric dipole moments of the top quark to -0.24 < C-tG/Lambda(2) < 0.07 TeV-2 and -0.33 < C-tG(I)/Lambda(2) < 0.20 TeV-2, respectively, at the 95% confidence level.FWFAustrian Science Fund (FWF); FNRSFonds de la Recherche Scientifique - FNRS; FWO (Belgium)FWO [30820817]; CNPqNational Council for Scientific and Technological Development (CNPq); CAPESCAPES; FAPERJCarlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ); FAPERGSFoundation for Research Support of the State of Rio Grande do Sul (FAPERGS); FAPESP (Brazil)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); MES (Bulgaria); MoST; NSFC (China)National Natural Science Foundation of China (NSFC); COLCIENCIAS (Colombia)Departamento Administrativo de Ciencia, Tecnologia e Innovacion Colciencias; CSF (Croatia); SENESCYT (Ecuador); MoER, ERC IUT, PUT; ERDF (Estonia)European Union (EU); Academy of FinlandAcademy of Finland; MEC; CEAFrench Atomic Energy Commission; CNRS/IN2P3 (France)Centre National de la Recherche Scientifique (CNRS); BMBFFederal Ministry of Education & Research (BMBF); DFGGerman Research Foundation (DFG); HGF (Germany); GSRT (Greece)Greek Ministry of Development-GSRT; NKFIA (Hungary); DAEDepartment of Atomic Energy (DAE); DSTDepartment of Science & Technology (India); IPM; SFI (Ireland)Science Foundation Ireland; INFN (Italy)Istituto Nazionale di Fisica Nucleare (INFN); NRF (Republic of Korea); MES (Latvia); MOEMinistry of Higher Education & Scientific Research (MHESR); UM (Malaysia); BUAP; CONACYTConsejo Nacional de Ciencia y Tecnologia (CONACyT); UASLP-FAI (Mexico); FCT (Portugal)Portuguese Foundation for Science and Technology; JINR (Dubna); RosAtom; RFBRRussian Foundation for Basic Research (RFBR); MESTD (Serbia); SEIDI; FEDER (Spain)European Union (EU); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); NSTDA; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); TAEKMinistry of Energy & Natural Resources - Turkey; NASU; SFFR; DOEUnited States Department of Energy (DOE); NSFNational Science Foundation (NSF); Marie-Curie programEuropean Union (EU); European Research CouncilEuropean Research Council (ERC); Horizon 2020 Grant [675440, 752730, 765710]; 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 (IWTBelgium)Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT); F. R. S.-FNRSFonds de la Recherche Scientifique - FNRS; Beijing Municipal Science AMP; Technology CommissionBeijing Municipal Science & Technology Commission [Z181100004218003]; Ministry of Education, Youth and Sports (MEYS) of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic; Janos Bolyai Research Scholarship of the Hungarian Academy of SciencesHungarian Academy of Sciences [123842, 123959, 124845, 124850, 125105, 128713, 128786, 129058]; Council of Science and Industrial Research, IndiaCouncil of Scientific & Industrial Research (CSIR) - India; HOMING PLUS program of the Foundation for Polish Science; European Union, Regional Development FundEuropean Union (EU); National Science Center (Poland)National Science Centre, PolandNational Science Center, Poland [Harmonia 2014/14/M/ST2/00428, 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, 2015/19/B/ST2/02861]; Sonata-bis [2012/07/E/ST2/01406]; National Priorities Research Program by Qatar National Research Fund; Ministry of Science and Education [3.2989.2017, MDM-20150509]; Programa Severo Ochoa del Principado de Asturias; Thalis and Aristeia programs; EU-ESFEuropean Union (EU); Greek NSRFGreek Ministry of Development-GSRT; Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University; Welch FoundationThe Welch Foundation [C-1845]; Weston Havens Foundation (USA); Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC) [ST/N000242/1] Funding Source: researchfishWe 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, PUT 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); MOSTR (Sri Lanka); 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). Rachada-pisek Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (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 (IWTBelgium); the F. R. S.-FNRS and FWO (Belgium) under the "Excellence of Science-EOS"-be.h Project No. 30820817; the Beijing Municipal Science & Technology Commission, No. Z181100004218003; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lendulet ("Momentum") Programme and the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program UNKP, the NKFIA research Grants No. 123842, No. 123959, No. 124845, No. 124850, No. 125105, No. 128713, No. 128786, and No. 129058 (Hungary); the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Ministry of Science and Education, Grant no. 3.2989.2017 (Russia); the Programa Estatal de Fomento de la Investigacion Cientifica y T ' ecnica de Excelencia Maria de Maeztu, grant No.; r MDM-20150509 and the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Welch Foundation, Contract No. C-1845; and the Weston Havens Foundation (USA)