A search for standard model production of four top quarks (t (t) over bart (t) over bar) is reported using events containing at least three leptons (e, mu) or a same-sign lepton pair. The events are produced in proton-proton collisions at a center-of-mass energy of 13 TeVat the LHC, and the data sample, recorded in 2016, corresponds to an integrated luminosity of 35.9 fb(-1). Jet multiplicity and flavor are used to enhance signal sensitivity, and dedicated control regions are used to constrain the dominant backgrounds. The observed and expected signal significances are, respectively, 1.6 and 1.0 standard deviations, and the t (t) over bart (t) over bar cross section ismeasured to be 16.9(-11.4)(+13.8) fb, in agreement with next-to-leading-order standard model predictions. These results are also used to constrain the Yukawa coupling between the top quark and the Higgs boson to be less than 2.1 times its expected standard model value at 95% confidence level.

Search for standard model production of four top quarks with same-sign and multilepton final states in proton-proton collisions at root s=13TeV

Abbrescia, M.;De Palma, M.;Errico, F.;Lezki, S.;Miniello, G.;My, S.;Nuzzo, S.;Pompili, A.;Selvaggi, G.;Venditti, R.;
2018

Abstract

A search for standard model production of four top quarks (t (t) over bart (t) over bar) is reported using events containing at least three leptons (e, mu) or a same-sign lepton pair. The events are produced in proton-proton collisions at a center-of-mass energy of 13 TeVat the LHC, and the data sample, recorded in 2016, corresponds to an integrated luminosity of 35.9 fb(-1). Jet multiplicity and flavor are used to enhance signal sensitivity, and dedicated control regions are used to constrain the dominant backgrounds. The observed and expected signal significances are, respectively, 1.6 and 1.0 standard deviations, and the t (t) over bart (t) over bar cross section ismeasured to be 16.9(-11.4)(+13.8) fb, in agreement with next-to-leading-order standard model predictions. These results are also used to constrain the Yukawa coupling between the top quark and the Higgs boson to be less than 2.1 times its expected standard model value at 95% confidence level.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11586/214135
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 54
  • ???jsp.display-item.citation.isi??? 41
social impact