Heavy-Higgs-boson production and vector-boson scattering processes ine+e−collisions at high energy

We study the reactions $e^{\mathrm{-}}$ $e^{+}$→νν¯ZZ and $e^{\mathrm{-}}$ $e^{+}$→$e^{\mathrm{-}}$ $e^{+}$ZZ using exact matrix elements. In particular, we examine the cross section for the production of a standard-model Higgs boson at several machine energies. In addition, we study the behavior of the vector-boson scattering processes when the Higgs-boson mass is infinite, focusing on the percentage of longitudinally polarized Z’s as a signature.