GAUGE INDEPENDENCE OF THE BUBBLE NUCLEATION RATE IN THEORIES WITH RADIATIVE SYMMETRY-BREAKING

In field theories where a metastable false vacuum state arises as a re sult of radiative corrections, the calculation of the rate of false va cuum decay by bubble nucleation depends on the effective potential and the other functions that appear in the derivative expansion of the ef fective action. Beginning with the Nielsen identity, we derive a serie s of identities that govern the gauge dependence of these functions. U sing these, we show, to leading nontrivial order, that, even though th ese functions are individually gauge dependent, one obtains a gauge-in dependent result for the bubble nucleation rate. Our formal arguments are complemented by explicit calculations for scalar electrodynamics i n a class of R(xi) gauges.