Consistent Use of the Standard Model Effective Potential

The stability of the Standard Model is determined by the true minimum of the effective Higgs potential. We show that the potential at its minimum when computed by the traditional method is strongly dependent on the gauge parameter. It moreover depends on the scale where the potential is calculated. We provide a consistent method for determining absolute stability independent of both gauge and calculation scale, order by order in perturbation theory. This leads to a revised stability bounds mH > (129.4 \pm 2.3) GeV and mt < (171.2 \pm 0.3)GeV. We also show how to evaluate the effect of new physics on the stability bound without resorting to unphysical field values.