Improved Higgs mass stability bound in the standard model and implications for supersymmetry

Abstract

We re-examine the lower bound on the mass of the Higgs boson, M h , from Standard Model vaccum stability including next-to-leading-log radiative corrections. This amounts to work with the full one-loop effective potential, V( θ), improved by two-loop RGE, and allows to keep control of the scale invariance of V in a wide range of the θ-field. Our results show that the bound is O (10 GeV) less stringent than in previous estimates. In addition we perform a detailed comparison between the SM lower bounds on M h and the supersymmetric upper bounds on it. It turns out that depending on the actual value of the top mass, M t , the eventually measured Higgs mass can discard the pure SM, the Minimal Supersymmetric Standard Model or both.