The recent results of the ATLAS and CMS experiments indicate $116\mathrm{GeV}\lesssim M_H\lesssim 131\mathrm{GeV}$ and $115\mathrm{GeV}\lesssim M_H\lesssim 127\mathrm{GeV}$, respectively, for the mass of the Higgs boson in the standard model (SM) at the 95% confidence level. In particular, both experiments point to a preferred narrow mass range $M_H\simeq (124\cdots 126)\mathrm{GeV}$. We examine the impact of this preliminary result of $M_H$ on the SM vacuum stability by using the two-loop renormalization-group equations, and arrive at the cutoff scale ${\Lambda }_{\mathrm{VS}}\sim 4\times {10}^{12}\mathrm{GeV}$ (for $M_H=125\mathrm{GeV}$, $M_t=172.9\mathrm{GeV}$, and ${\alpha }_s(M_Z)=0.1184$), where the absolute stability of the SM vacuum is lost and some kind of new physics might take effect. We update the values of running lepton and quark masses at some typical energy scales, including the ones characterized by $M_H$, 1 TeV and ${\Lambda }_{\mathrm{VS}}$, with the help of the two-loop renormalization-group equations. The branching ratios of some important two-body Higgs decay modes, such as $H\to b\overline{b}$, $H\to {\tau }^{+}{\tau }^{-}$, $H\to \gamma \gamma$, $H\to W^{+}{W}^{-}$, and $H\to ZZ$, are also recalculated by inputting the values of relevant particle masses at $M_H$.

• Received 4 May 2012

DOI:https://doi.org/10.1103/PhysRevD.86.013013