@article{eaa965769d5f421ab9fffb94bd033603,
title = "Evidence for four-top quark production in proton-proton collisions at s=13TeV",
abstract = "The production of four top quarks (tt¯tt¯) is studied with LHC proton-proton collision data samples collected by the CMS experiment at a center-of-mass energy of 13 TeV, and corresponding to integrated luminosities of up to 138fb−1. Events that have no leptons (all-hadronic), one lepton, or two opposite-sign leptons (where lepton refers only to prompt electrons or prompt muons) are considered. This is the first tt¯tt¯ measurement that includes the all-hadronic final state. The observed significance of the tt¯tt¯ signal in these final states of 3.9 standard deviations (1.5 expected) provides evidence for tt¯tt¯ production, with a measured cross section of 36−11+12fb. Combined with earlier CMS results in other final states, the signal significance is 4.0 standard deviations (3.2 expected). The combination returns an observed cross section of 17±4(stat)±3(syst)fb, which is consistent with the standard model prediction.",
keywords = "CMS, Top quark",
author = "{The CMS collaboration} and A. Tumasyan and W. Adam and Andrejkovic, {J. W.} and T. Bergauer and S. Chatterjee and K. Damanakis and M. Dragicevic and {Escalante Del Valle}, A. and Hussain, {P. S.} and M. Jeitler and N. Krammer and L. Lechner and D. Liko and I. Mikulec and P. Paulitsch and J. Schieck and R. Sch{\"o}fbeck and D. Schwarz and M. Sonawane and S. Templ and W. Waltenberger and Wulz, {C. E.} and Darwish, {M. R.} and T. Janssen and T. Kello and {Rejeb Sfar}, H. and {Van Mechelen}, P. and Bols, {E. S.} and J. D'Hondt and {De Moor}, A. and M. Delcourt and {El Faham}, H. and S. Lowette and A. Morton and D. M{\"u}ller and Sahasransu, {A. R.} and S. Tavernier and {Van Doninck}, W. and {Van Putte}, S. and D. Vannerom and B. Clerbaux and S. Dansana and {De Lentdecker}, G. and L. Favart and D. Hohov and J. Jaramillo and K. Lee and M. Mahdavikhorrami and I. Makarenko and A. Moraes",
note = "Funding Information: 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 and other centers 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, the CMS detector, and the supporting computing infrastructure provided by the following funding agencies: BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq , CAPES , FAPERJ , FAPERGS , and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN ; CAS , MOST , and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER , ERC PUT and ERDF (Estonia); Academy of Finland , MEC , and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF , DFG , and HGF (Germany); GSRI (Greece); NKFIH (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); MES and NSC (Poland); FCT (Portugal); MESTD (Serbia); MCIN/AEI and PCTI (Spain); MoSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); MHESI and NSTDA (Thailand); TUBITAK and TENMAK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Funding Information: Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440 , 724704 , 752730 , 758316 , 765710 , 824093 , 884104 , and COST Action CA16108 (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 {\`a} la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the “Excellence of Science – EOS” – be.h project n. 30820817 ; the Beijing Municipal Science & Technology Commission , No. Z191100007219010 ; The Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Hellenic Foundation for Research and Innovation (HFRI), Project Number 2288 (Greece); the Deutsche Forschungsgemeinschaft (DFG), under Germany's Excellence Strategy – EXC 2121 “Quantum Universe” – 390833306 , and under project number 400140256 - GRK2497 ; the Hungarian Academy of Sciences , the New National Excellence Program - {\'U}NKP, the NKFIH research grants K 124845 , K 124850 , K 128713 , K 128786 , K 129058 , K 131991 , K 133046 , K 138136 , K 143460 , K 143477 , 2020-2.2.1-ED-2021-00181 , and TKP2021-NKTA-64 (Hungary); the Council of Science and Industrial Research , India; the Latvian Council of Science ; the Ministry of Education and Science , project no. 2022/WK/14 , and the National Science Center , contracts Opus 2021/41/B/ST2/01369 and 2021/43/B/ST2/01552 (Poland); the Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia , grant CEECIND/01334/2018 (Portugal); MCIN/AEI/10.13039/501100011033, ERDF “a way of making Europe” , and the Programa Estatal de Fomento de la Investigaci{\'o}n Cient{\'i}fica y T{\'e}cnica de Excelencia Mar{\'i}a de Maeztu , grant MDM-2017-0765 and Programa Severo Ochoa del Principado de Asturias (Spain); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project , and the National Science, Research and Innovation Fund via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation , grant B05F650021 (Thailand); the Kavli Foundation ; the Nvidia Corporation; the SuperMicro Corporation ; the Welch Foundation , contract C-1845 ; and the Weston Havens Foundation (USA). Publisher Copyright: {\textcopyright} 2023 The Author(s)",
year = "2023",
month = sep,
day = "10",
doi = "10.1016/j.physletb.2023.138076",
language = "English",
volume = "844",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
}