Stability, Higgs Boson Mass and New Physics

When the particle with mass $\sim 126$ GeV discovered at LHC is identified with the Higgs boson of the Standard Model, intriguing and challenging questions arise. Among them, the issue of the EW vacuum stability. We find that, despite claims to the contrary, the latter strongly depends on new physics interactions. In particular, if $\tau$ is the lifetime of the EW vacuum, new physics can turn $\tau$ from $\tau >> T_U$ to $\tau << T_U$, where $T_U$ is the age of the Universe.