par Hayrapetyan, A.;Clerbaux, Barbara 
;De Lentdecker, Gilles ;Favart, Laurent ;Hohov, Dmytro ;Jaramillo Gallego, Johny ;Khalilzadeh, Ali ;Lee, Kyeongpil ;Mahdavikhorrami, Mostafa ;Malara, Andrea ;Paredes Saenz, Santiago ;Pétré, Laurent ;Postiau, Nicolas ;Thomas, Laurent ;Vanden Bemden, Max ;Vander Velde, Catherine ;Vanlaer, Pascal ; [et al.]
Référence Physics letters. Section B, 847, 138290
Publication Publié, 2023-01-01
;De Lentdecker, Gilles ;Favart, Laurent ;Hohov, Dmytro ;Jaramillo Gallego, Johny ;Khalilzadeh, Ali ;Lee, Kyeongpil ;Mahdavikhorrami, Mostafa ;Malara, Andrea ;Paredes Saenz, Santiago ;Pétré, Laurent ;Postiau, Nicolas ;Thomas, Laurent ;Vanden Bemden, Max ;Vander Velde, Catherine ;Vanlaer, Pascal ; [et al.]Référence Physics letters. Section B, 847, 138290
Publication Publié, 2023-01-01
Article révisé par les pairs
| Résumé : | The observation of the production of four top quarks in proton-proton collisions is reported, based on a datasample collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016–2018 at the CERN LHCand corresponding to an integrated luminosity of 138 fb−1. Events with two same-sign, three, or four chargedleptons (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, aswell as a revised multivariate analysis strategy to distinguish the signal process from the main backgrounds, leadto 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 ismeasured to be 17.7 +3.7−3.5 (stat) +2.3−1.9 (syst) fb, in agreement with the available standard model predictions |
