abstract:
The Higgs boson, discovered two years ago at LHC, is the last ingredient necessary for the self-consistency of the Standard Model. This discovery poses a number of questions, in particular it clashes with the concept of naturalness. Even long before 2012 the Higgs sector of the Standard Model had been considered somewhat unnatural; now the discovery of the scalar boson makes the contrast with naturalness more evident, since the expected new physics has not been found. Here I sketch the theoretical arguments about the Higgs sector, before and after the discovery of two years ago; moreover I shortly illustrate one of the models which ignore naturalness, at least as presently conceived.