Observation of four top quark production in proton-proton collisions at √s=13 TeV
The observation of the production of four top quarks in proton-proton collisions is reported, based on a data sample collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016-2018 at the CERN LHC and corresponding to an integrated luminosity of 138 fb-1. Events with two same-sign, three, or four charged leptons (electrons and muons) and additional jets are analyzed. Compared to previous results in these channels, updated identification techniques for charged leptons and jets originating from the hadronization of b quarks, as well as a revised multivariate analysis strategy to distinguish the signal process from the main backgrounds, lead to an improved expected signal significance of 4.9 standard deviations above the background-only hypothesis. Four top quark production is observed with a significance of 5.6 standard deviations, and its cross section is measured to be 17.7+3.7-3.5 (stat)+2.3-1.9 (syst) fb, in agreement with the available standard model predictions.
WOS:001123208000001
2023-12-10
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Funder | Grant Number |
COST Action | 675440 |
Leventis Foundation | CA16108 |
Alfred P. Sloan Foundation | |
Alexander von Humboldt Foundation | |
Belgian Federal Science Policy Office | |
Fonds pour la Formation la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium) | |
Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium) | |
FWO (Belgium) | 30820817 |
Beijing Municipal Science & Technology Commission | |
Min-istry of Education, Youth and Sports (MEYS) of the Czech Republic | Z191100007219010 |
Hellenic Foundation for Research and Innovation (HFRI) | 2288 |
Deutsche Forschungsgemeinschaft (DFG) | |
Hungarian Academy of Sciences | EXC 2121 |
Council of Science and Industrial Research, India | K 124845 |
Ministry of Education and Science | 2022/WK/14 |
National Science Center | |
National Priorities Research Program by Qatar National Research Fund | Opus 2021/41/B/ST2/01369 |
ERDF "a way of making Europe | MDM-2017-0765 |
Programa Severo Ochoa del Principado de As-turias (Spain) | |
National Science, Research and Innova-tion Fund via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation | B05F650021 |
Kavli Foundation | |
Nvidia Corporation | |
Welch Foundation | C-1845 |
Weston Havens Foundation (USA) | |