Abstract

A procedure is given to estimate the decay probability of a metastable vacuum state in quantum field theory. As an application, in the Weinberg-Salam model the lower bound (for ${\ensuremath{\theta}}_{\mathrm{W}}=35\ifmmode^\circ\else\textdegree\fi{}$) on the Higgs mass can be reduced from 4.9 GeV, corresponding to effective stability of a metastable vacuum.