Precision from the diphoton Zh channel at FCC-hh

Abstract

The future 100 TeV FCC-hh hadron collider will give access to rare but clean final states which are out of reach of the HL-LHC. One such process is the Zh production channel in the left(voverline{v}/{mathrm{ell}}^{+}{mathrm{ell}}^{-}right)gamma gamma final states. We study the sensitivity of this channel to the {mathcal{O}}_{varphi q}^{(1)},kern0.5em {mathcal{O}}_{varphi q}^{(3)},kern0.5em {mathcal{O}}_{varphi u} , and {mathcal{O}}_{varphi d} SMEFT operators, which parametrize deviations of the W and Z couplings to quarks, or, equivalently, anomalous trilinear gauge couplings (aTGC). While our analysis shows that good sensitivity is only achievable for {mathcal{O}}_{varphi q}^{(3)} , we demonstrate that binning in the Zh rapidity has the potential to improve the reach on {mathcal{O}}_{varphi q}^{(1)} . Our estimated bounds are one order of magnitude better than projections at HL-LHC and is better than global fits at future lepton colliders. The sensitivity to {mathcal{O}}_{varphi q}^{(3)} is competitive with other channels that could probe the same operator at FCC-hh. Therefore, combining the different diboson channels sizeably improves the bound on {mathcal{O}}_{varphi q}^{(3)} , reaching a precision of |δg1z| ≲ × 10−4 on the deviations in the ZWW interactions.