Search for H gamma resonance in boosted large-R jet plus photon final states in pp collisions at √s=13 TeV with the ATLAS detector

Many extensions of the Standard Model predict a new particle that decays into a Standard Model Higgs boson and a photon. In 2018, a search for a heavy resonance in final states with a hadronically Z/W/H boson and a photon shows that the 2015+2016 data are consistent with the Standard Model expectation. This talk presents an updated search with an integrated luminosity of 140 fb-1 (from 2015 to 2018) collected by the ATLAS detector at the Large Hadron Collider to search for such resonances produced in pp collisions at √s=13 TeV. In the analysis, boosted hadronically decaying Higgs bosons are reconstructed as single jets and identified through their decays to b-hadrons by a new tagging technique: center of mass (CoM) algorithm. In this talk, we will describe the analysis strategy, the new CoM algorithm and its expected improvement of experimental sensitivity comparing to previous searches.