Search for ttH production in events where H decays to photons at 8 TeV collisions

We present the results of the search for the associated production of the Higgs boson with a $t \bar{t}$ pair, using for the first time the events where the Higgs boson decays to two photons. To maximize acceptance and sensitivity to such a small signal, we device two different sets of event selection criteria, optimized for leptonic and hadronic $\mathrm{t \bar t}$ decays. We analyze 19.6\,fb$^{-1}$ of 8\,TeV $\mathrm{pp}$ collisions and found no significant excess over the background-only predictions. We thus proceed to set an observed (expected) 95\% confidence level upper limit on the $\mathrm{t \bar t H}$ production cross section times $BR(H \to \gamma \gamma)$ of 5.4 (5.3) times the standard model value, corresponding to 1.6~fb, for a Higgs boson of $m_{H} = 125$\,GeV.