Fermilab - IARC
ATLAS ttH measurements in the H-> gamma gamma channel
Higgs production in association with top quarks (ttH) is predicted by the Standard Model at a rate of about 1% of the total Higgs cross section. This process directly probes the Higgs-top coupling, a critical parameter for isolating Beyond the Standard Model contributions to Higgs physics. The ATLAS search for ttH events in conjunction with the decay H → γγ takes advantage of the high photon detection efficiency and energy resolution of the ATLAS electro-magnetic calorimeter, as well as the relatively low rate of diphoton background processes. The application of sophisticated multivariate techniques to identify ttH → γγ events improves the sensitivity to ttH compared to past analyses. In combination with other Higgs decay channels, ttH → γγ contributed to the recent discovery of the ttH production mode.