Search for the production of four top quarks in the single-lepton and opposite-sign dilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV

Abstract A search for the standard model production of four top quarks (pp → tt¯tt¯$$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$) is reported using single-lepton plus jets and opposite-sign dilepton plus jets signatures. Proton-proton collisions are recorded w...

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Bibliographic Details
Main Authors: Sirunyan, A. M, Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., Dragicevic, M., Erö, J., Escalante Del Valle, A., Flechl, M., Frühwirth, R., Jeitler, M., Krammer, N., Krätschmer, I., Liko, D., Madlener, T., Mikulec, I., Rad, N.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2021
Online Access:https://hdl.handle.net/1721.1/131647
Description
Summary:Abstract A search for the standard model production of four top quarks (pp → tt¯tt¯$$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$) is reported using single-lepton plus jets and opposite-sign dilepton plus jets signatures. Proton-proton collisions are recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV in a sample corresponding to an integrated luminosity of 35.8 fb−1. A multivariate analysis exploiting global event and jet properties is used to discriminate tt¯tt¯$$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$ from tt¯$$ \mathrm{t}\overline{\mathrm{t}} $$ production. No significant deviation is observed from the predicted background. An upper limit is set on the cross section for tt¯tt¯$$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$ production in the standard model of 48 fb at 95% confidence level. When combined with a previous measurement by the CMS experiment from an analysis of other final states, the observed signal significance is 1.4 standard deviations, and the combined cross section measurement is 13−9+11$$ {13}_{-9}^{+11} $$ fb. The result is also interpreted in the framework of effective field theory.