Prospects for $\gamma \gamma \to$ Higgs observation in ultraperipheral ion collisions at the Future Circular Collider

Abstract

We study the two-photon production of the Higgs boson, $\gamma \gamma \to \mathrm{H}$, at the Future Circular Collider (FCC) in ultraperipheral PbPb and pPb collisions at $\sqrt{s_{NN}}=39$ and 63 TeV. Signal and background events are generated with MADGRAPH 5, including $\gamma$ fluxes from the proton and lead ions in the equivalent photon approximation, yielding $\sigma (\gamma \gamma \to \mathrm{H})$ = 1.75 nb and 1.5 pb in PbPb and pPb collisions respectively. We analyse the H$\to b\bar{b}$ decay channel including realistic reconstruction efficiencies for the final-state $b$-jets, showered and hadronized with PYTHIA 8, as well as appropriate selection criteria to reduce the dominant exclusive $\gamma \gamma \to b\bar{b}$ continuum background. Observation of $\mathrm{PbPb}\stackrel{\gamma \gamma }{\to }(\mathrm{Pb})\mathrm{H}(\mathrm{Pb})$ is achievable in the first year with the expected PbPb integrated luminosities.

Comments: 5 pages, 4 figures. PHOTON'17, CERN Proceedings, to appear. References added