Feasibility study of single top-quark and top-quark pair production in association with a Higgs Boson and a Photon at the LHC

A feasibility study for the Standard Model Higgs boson produced in association with a single top-quark or a top-quark pair and a photon (\tHa\, and \ttHa) is presented, using simulated pp collision data corresponding to an integrated luminosity of 350 fb$^{-1}$ at $\sqrt{s}=13.6$ TeV. This study was conducted using simulated data generated with MadGraph. The study was performed in the context of the CMS experiment, where detector effects were incorporated using Delphes. Final states are selected through the leptonic decay of W boson, and the Higgs boson decays to two b-quarks. Signal events are separated from background events using multivariate techniques such as Boosted Decision Trees (BDT). The expected cross section for single top-quark production in association with a Higgs boson and a photon, $\sigma$(\tHa), was measured to be 1.31 fb at 13.6 TeV, with a significance of 7.5 standard deviations from the background-only hypothesis for a luminosity of 350 fb$^{-1}$ at 13.6 TeV. The expected cross section for $\sigma$(\ttHa) was measured to be $2.94^{+0.196}_{-0.276}$ fb at 13.6 TeV, with a significance of 6.6 standard deviations from the background-only hypothesis for a luminosity of 350\,fb$^{-1}$ at 13.6 TeV. Importantly, both the \tHa\, and \ttHa\, processes are already feasible with the currently accumulated Run 3 dataset, demonstrating strong potential for early measurements.