We evaluate the $e^{-}{e}^{+}\to e^{-}{e}^{+}+h$ process through the $ZZ$ fusion channel at the International Linear Collider operating at 500 GeV and 1 TeV center-of-mass energies. We perform realistic simulations on the signal process and background processes. With judicious kinematic cuts, we find that the inclusive cross section can be measured to 2.9% after combining the 500 GeV at $500{\mathrm{fb}}^{-1}$ and 1 TeV at $1{\text{ab}}^{-1}$ runs. A multivariate log-likelihood analysis further improves the precision of the cross section measurement to 2.3%. We discuss the overall improvement to model-independent Higgs width and coupling determinations and demonstrate the use of different channels in distinguishing new physics effects in Higgs physics. Our study demonstrates the importance of the $ZZ$ fusion channel to Higgs precision physics, which has often been neglected in the literature.

• Received 30 April 2015

DOI:https://doi.org/10.1103/PhysRevD.91.113007