TY - JOUR
T1 - Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector
AU - Clark, Philip James
AU - Farrington, Sinead
AU - Faucci Giannelli, Michele
AU - Gao, Yanyan
AU - Hasib, Ahmed
AU - Leonidopoulos, Christos
AU - Martin, Victoria Jane
AU - Mijović, Liza
AU - Wynne, Benjamin
AU - Collaboration, Atlas
PY - 2018/4/9
Y1 - 2018/4/9
N2 - A search for the associated production of the Higgs boson with a top quark pair ($t\bar t H$) is reported. The search is performed in multilepton final states using a dataset corresponding to an integrated luminosity of 36.1 fb$^{-1}$ of proton--proton collision data recorded by the ATLAS experiment at a center-of-mass energy $\sqrt{s} = 13$ TeV at the Large Hadron Collider. Higgs boson decays to $WW^*$, $\tau\tau$, and $ZZ^*$ are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the $t\bar t H$ production cross section is $\sigma(t\bar t H) = 790^{+230}_{-210}$ fb, in agreement with the Standard Model prediction of $507^{+35}_{-50}$ fb. The combination of this result with other $t\bar t H$ searches from the ATLAS experiment using the Higgs boson decay modes to $b\bar b$, $\gamma\gamma$ and $ZZ^* \to 4\ell$, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the $t\bar t H$ production mode.
AB - A search for the associated production of the Higgs boson with a top quark pair ($t\bar t H$) is reported. The search is performed in multilepton final states using a dataset corresponding to an integrated luminosity of 36.1 fb$^{-1}$ of proton--proton collision data recorded by the ATLAS experiment at a center-of-mass energy $\sqrt{s} = 13$ TeV at the Large Hadron Collider. Higgs boson decays to $WW^*$, $\tau\tau$, and $ZZ^*$ are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the $t\bar t H$ production cross section is $\sigma(t\bar t H) = 790^{+230}_{-210}$ fb, in agreement with the Standard Model prediction of $507^{+35}_{-50}$ fb. The combination of this result with other $t\bar t H$ searches from the ATLAS experiment using the Higgs boson decay modes to $b\bar b$, $\gamma\gamma$ and $ZZ^* \to 4\ell$, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the $t\bar t H$ production mode.
U2 - 10.1103/PhysRevD.97.072003
DO - 10.1103/PhysRevD.97.072003
M3 - Article
SN - 0556-2821
VL - D97
JO - Physical Review D, particles, fields, gravitation, and cosmology
JF - Physical Review D, particles, fields, gravitation, and cosmology
IS - 7
M1 - 072003
ER -