Complete wetting in three dimensions II. Renormalization of the capillary parameter

We present a renormalization group (RG) analysis of critical effects at the complete wetting transition for three-dimensional systems with short-ranged forces based on the two-field Hamiltonian HI(2) [l1, l2] introduced in paper (I). We show that the effective value of the capillary parameter determining critical amplitudes is changed under RG flow due to coupling between spin fluctuations near the wall and the depinning fluid interface. We compare our predictions with data from recent Ising model Monte Carlo studies which probe finite-size effects at complete wetting presenting what we believe to be the correct interpretation of the simulation results. We find good quantitative agreement and emphasize that this could not be achieved using a standard effective Hamiltonian approach.