Higgs signals and hard photons at the Next Linear Collider: the $ZZ$-fusion channel in the Standard Model

Abstract

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 presence of electromagnetic radiation due real photon emission. Calculations are carried out at tree-level and rates of the leading order (LO) processes $e^+e^-\rightarrow e^+e^- H \ar e^+e^- b\bar b $ and $e^+e^-\rightarrow e^+e^- H \ar e^+e^- WW \ar e^+e^- \mathrm{jjjj}$ are compared to those of the next-to-leading order (NLO) reactions $e^+e^-\rightarrow e^+e^- H (\gamma)\ar e^+e^- b\bar b \gamma$ and $e^+e^-\rightarrow e^+e^- H (\gamma)\ar e^+e^- WW (\gamma) \ar e^+e^- \mathrm{jjjj}\gamma$, in the case of energetic and isolated photons.