A search for the standard model production of four top quarks (pp → $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$) 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 $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$from $$ \mathrm{t}\overline{\mathrm{t}} $$production. No significant deviation is observed from the predicted background. An upper limit is set on the cross section for $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$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 $$ {13}_{-9}^{+11} $$fb. The result is also interpreted in the framework of effective field theory.

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

P. Montagna;S. P. Ratti;M. Ressegotti;C. Riccardi;P. Salvini;I. Vai;P. Vitulo;
2019-01-01

Abstract

A search for the standard model production of four top quarks (pp → $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$) 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 $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$from $$ \mathrm{t}\overline{\mathrm{t}} $$production. No significant deviation is observed from the predicted background. An upper limit is set on the cross section for $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{t}\overline{\mathrm{t}} $$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 $$ {13}_{-9}^{+11} $$fb. The result is also interpreted in the framework of effective field theory.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/1488677
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