Higgs boson analysis

Our group is actively involved in analysing the properties of the Higgs boson. Since the discovery of the Higgs boson, our group has participated in the analysis of the Higgs boson physics by looking a several different production and decay channels:

• $t \bar t H$, $H\rightarrow \gamma \gamma$, production of a Higgs boson with a top-quark pair, with the Higgs boson decaying into two photons.  We have been investigating the backgrounds and the modelling of the signal  (Dr Hasib Ahmed, Prof Phil Clark, Prof Victoria Martin, Dr Liza Mijovic, Alan Taylor)
• $HH \rightarrow \gamma\gamma b \bar b$: we are looking for di-Higgs boson production in the $\gamma\gamma b \bar b$ final state.  This search is sensitive to beyond-the-Standard-Model physics that would produce two Higgs boson (Prof Victoria Martin, Alan Taylor)
• Higgs boson prospects: investigating the potential of the upgraded ATLAS experiment to discover rare Higgs boson phenomena and make precise measurements of the High Luminosity-LHC.  Our group has worked on the prospects for $t \bar t HH$  and $W/ZH$ production   (Prof Victoria Martin, Alan Taylor)
• $H \rightarrow Z Z^* \rightarrow 4 \ell$: We played a leading role in the measurements of the mass, signal strength and width in the “golden” four-lepton channel (Prof Phil Clark, Dr Christos Leonidopoulos, Dr Ben Wynne)
• $W/Z \,H$ associated production of the Higgs boson with a $W$ or $Z$ boson with the Higgs boson decaying to $b \bar{b}$: We have worked on the search of the Higgs boson in this channel  ( Prof Phil Clark, Prof Victoria Martin)
• $H \rightarrow WW \rightarrow \ell \nu \, \ell^\prime \nu^\prime$: We were key contributors to the analysis of the Higgs boson in the $WW$ decay channel in the fully leptonic mode, specializing in data-driven background estimation and performing the first differential cross sections in this channel.

These activities are led by Prof Phil Clark and Prof Victoria Martin.