Observation of four top quark production in proton-proton collisions at √s=13TeV

Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Escalante Del Valle, A.; Hussain, P.S.; Bevilacqua, T.; Caminada, L.; Ebrahimi, A.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H.C.; Kotlinski, D.; Lange, C.; Missiroli, M.; Noehte, L.; Rohe, T.; Zhokin, A.

doi:10.1016/j.physletb.2023.138290

Observation of four top quark production in proton-proton collisions at √s=13TeV

Hayrapetyan A, Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, Dragicevic M, Escalante Del Valle A, Hussain PS, Bevilacqua T, Caminada L, Ebrahimi A, Erdmann W, Horisberger R, Ingram Q, Kaestli HC, Kotlinski D, Lange C, Missiroli M, Noehte L, Rohe T, Zhokin A, et al.

Citation

Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., … Zhokin, A. (2023). Observation of four top quark production in proton-proton collisions at √s=13TeV. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 847, 138290 (23 pp.). https://doi.org/10.1016/j.physletb.2023.138290

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:60430

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 138fb⁻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_−3.5^+3.7(stat)_−1.9^+2.3(syst)fb, in agreement with the available standard model predictions.

Details

Publication Type

Journal Article

Title

Observation of four top quark production in proton-proton collisions at √s=13TeV

Author(s)

Hayrapetyan, A.

Tumasyan, A.

Adam, W.

Andrejkovic, J.W.

Bergauer, T.

Chatterjee, S.