Two-loop large Higgs mass corrections to electroweak gauge boson quartic couplings

The two-loop corrections to the electroweak gauge boson quartic couplings, growing quadratically with the Higgs boson mass, are calculated in the Standard Model in the limit of large Higgs mass. The corrections to WWWW, WWZZ and ZZZZ four-vertices are found to be an order of magnitude larger than the two-loop mH2 corrections to light fermion and triple gauge boson vertices. For a heavy Higgs boson with a mass around 1 TeV the corrections are at the several percent level and in principle could be observed experimentally.