Massive neutrinos and the Higgs boson mass window

In the standard model, if there is no new physics up to a certain scale, there is a window for the Higgs boson mass, defined by the upper (perturbativity) and the lower (stability) bounds. If the new physics is in the form of right-handed neutrinos, responsible for the small neutrino masses through a seesaw mechanism, then the window narrows, and even disappears for M (the right-handed Majorana mass) ranging from (Formula presented) for three quasidegenerate neutrinos with (Formula presented) to (Formula presented) for just one relevant generation with (Formula presented) A slightly weaker upper bound on M, coming from the requirement that the neutrino Yukawa couplings do not develop a Landau pole, is also discussed.