Two-loop O(αsGFmt2) corrections to Higgs production at LEP Original Research Article

We evaluate the two-loop O(αsGFmt2) correction to the ZZH coupling in the Standard Model by means of a low-energy theorem, assuming that the top quark is much heavier than the Higgs boson. We then construct a heavy-top-quark effective Lagrangian for the ZZH interaction that accommodates the O(GFmt2) and O(αsGFmt2) corrections and derived from it the corresponding corrections to the H → ZZ decay as well as those to Higgs-boson production at LEP1, via Z → ƒƒH and at LEP2, via e+e− → ZH. In all cases, the leading O(GFmt2) terms are considerably screened by their QCD corrections, if the on-shell renormalization scheme with GF as a basic parameter is employed.