Measurement of the associated production of a Higgs boson and a pair of top-antitop quarks with the Higgs boson decaying to two photons in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$

This document reports the measurement of the rate of the associated production of a Higgs boson and a pair of top-antitop quarks (t$\bar{\text{t}}$H), with the Higgs boson decaying into a pair of photons. Events with two photons are selected from a sample of proton-proton collisions at a center-of-mass energy $\sqrt{s}=13~\mathrm{TeV}$ collected by the CMS detector at the LHC in 2017, corresponding to an integrated luminosity of $41.5~\mathrm{fb}^{-1}$. The t$\bar{\text{t}}$H production is identified by requiring the presence of top quark decay products in the final state. The measured cross section, normalized to the standard model prediction, is 1.3$^{+0.7}_{-0.5}$. The combination with the published result using $35.9~\mathrm{fb}^{-1}$ of data recorded in 2016 at a center-of-mass energy $\sqrt{s}=13~\mathrm{TeV}$ is also reported. The combined best fit cross section, normalized to the standard model prediction, is found to be 1.7$^{+0.6}_{-0.5}$. All results are found in agreement with the standard model expectation.