Higgs signals and hard photons at the Next Linear Collider: the ZZ-fusion channel in the standard model

In this paper, we extend the analyses carried out in a previous article for WW-fusion to the case of Higgs production via ZZ-fusion within the standard model at the Next Linear Collider, in the presence of electromagnetic radiation due to real photon emission. Calculations are carried out at tree-level and rates of the leading order (LO) processes e+e- → e+e-H → e+e-bb-bar and e+e- → e+e-H → e+e-WW → e+e-jjjj are compared to those of the next-to-leading order (NLO) reactions e+e- → e+e-H(γ) → e+e-bb-barγ and e+e- → e+e-H(γ) → e+e-WW(γ) → e+e-jjjjγ, in the case of energetic and isolated photons. (author)