Gauge Independent Effective Potential and the Higgs Mass Bound
  We introduce the Vilkovisky-DeWitt formalism for deriving the lower bound of the Higgs boson mass.   We illustrate the formalism with a simplified version of the Standard Electroweak Model, where all charged boson fields as well as the bottom-quark field are disregarded. The effective potential obtained in this approach is gauge independent. We derive from the effective potential the mass bound of the Higgs boson. The result is compared to its counterpart obtained from the ordinary effective potential. 
Guey-Lin Lin and Tzu-Kang Chyi