Orateur
Description
A search for the resonant production of a heavy scalar X decaying into a Higgs boson and
a new lighter scalar S, through the process X$\rightarrow$ S ($b\bar{b}$) H($\gamma \gamma$), where the two photons are consistent with the Higgs boson decay, is performed. The search is conducted using 140 fb$^{-1}$ of LHC Run 2 data recorded by ATLAS. The mass space investigated in the analysis is 170 $\leq$ mX $\leq$ 1000 GeV and 15 $\leq$ mS $\leq$ 500 GeV. Parameterised Neural Networks (PNN) are used to enhance the signal purity and to achieve continuous sensitivity in a domain of the (mX, mS) mass plane.
A log-likelihood fit is performed on the PNN score distribution to look for an excess with respect to expected background compatible with X$\rightarrow$ S ($b\bar{b}$) H($\gamma \gamma$) signal.
If no excess is found, model independent upper limits will be set on the cross section times branching ratio.
