Improved Higgs Mass Stability Bound in the Standard Model and Implications for Supersymmetry

TL;DR

The paper re-evaluates the Standard Model vacuum stability bound on the Higgs mass by employing the full one-loop effective potential $V(\phi)$ enhanced with two-loop RGEs, ensuring a largely scale-invariant determination of electroweak symmetry breaking. It demonstrates that the lower bound on $M_H$ is about ${\cal O}(10\ \mathrm{GeV})$ weaker than prior estimates and analyzes the large-$\phi$ behavior of the potential to relate stability to the cutoff $\Lambda$. The authors compare SM bounds with MSSM upper bounds, showing that the viability of a measured Higgs mass depends critically on $M_t$ and SUSY parameters, and they provide analytic fits for the bounds as functions of $M_t$ and $\alpha_S$. Overall, the work refines Higgs mass constraints and clarifies how Higgs measurements could discriminate between the Standard Model and supersymmetric extensions at current and future colliders.

Abstract

We re-examine the lower bound on the mass of the Higgs boson, $M_H$, from Standard Model vacuum stability including next-to-leading-log radiative corrections. This amounts to work with the full one-loop effective potential, $V(φ)$, improved by two-loop RGE, and allows to keep control of the scale invariance of $V$ in a wide range of the $φ$-field. Our results show that the bound is ${\cal O}\ (10\ GeV)$ 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.