Naslov
Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at $\sqrt{;s}; =$ 13 TeV

Autori
Sirunyan, Albert M ; ... ; Antunović, Željko ; Brigljević, Vuko ; Ferenček, Dinko ; Giljanović, Duje ; Godinović, Nikola ; Kovač, Marko ; Lelas, Damir ; Majumder, Devdatta ; Puljak, Ivica ; Roguljić, Matej ; Starodumov, Andrey ; Đurić, Senka ; Šuša, Tatjana ; Šćulac, Toni ; ... ; Vetens, Wren

Kolaboracija
CMS Collaboration

Izvornik
European physical journal C : particles and fields (1434-6044) 81 (2021), 4; 378, 51

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
High energy physics ; Experimental particle physics ; LHC ; CMS ; Hadron-Hadron scattering (experiments) ; Higgs physics ; p p: colliding beams ; Higgs particle: pair production ; bottom: 2 ; p p: scattering ; Higgs particle: coupling ; Higgs particle: hadroproduction ; Higgs particle: decay modes ; bottom: pair production ; photon: pair production ; top: pair production ; coupling: Yukawa ; coupling constant: upper limit ; vector boson: fusion ; mass spectrum: two-photon ; Standard model

Sažetak
The rate for Higgs (H) bosons production in association with either one (tH) or two ($\mathrm{;t\bar{;t};};$H) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton-proton collisions recorded at a center-of-mass energy of 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137 fb$^{;-1};$. The analysis is aimed at events that contain H $\to$ WW, H $\to$ $\tau\tau$, or H $\to$ ZZ decays and each of the top quark(s) decays either to lepton+jets or all-jet channels. Sensitivity to signal is maximized by including ten signatures in the analysis, depending on the lepton multiplicity. The separation among the tH, the $\mathrm{;t\bar{;t};};$H, and the backgrounds is enhanced through machine-learning techniques and matrix-element methods. The measured production rates for the $\mathrm{;t\bar{;t};};$H and tH signals correspond to 0.92 $\pm$ 0.19 (stat) $^{;+0.17};_{;-0.13};$ (syst) and 5.7 $\pm$ 2.7 (stat) $\pm$ 3.0 (syst) of their respective standard model (SM) expectations. The corresponding observed (expected) significance amounts to 4.7 (5.2) standard deviations for $\mathrm{;t\bar{;t};};$H, and to 1.4 (0.3) for tH production. Assuming that the Higgs boson coupling to the tau lepton is equal in strength to its expectation in the SM, the coupling $y_{;\mathrm{;t};};$ of the Higgs boson to the top quark divided by its SM expectation, $\kappa_\mathrm{;t};$ = $y_\mathrm{;t}; / y_\mathrm{;t};^\mathrm{;SM};$, is constrained to be within $-$0.9 $\lt$ $\kappa_\mathrm{;t};$ $\lt$ $-$0.7 or 0.7 $\lt$ $\kappa_\mathrm{;t};$ $\lt$ 1.1, at 95% confidence level. This result is the most sensitive measurement of the $\mathrm{;t\bar{;t};};$H production rate to date.

Izvorni jezik
Engleski

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