Chiral Symmetry Breaking from Renormalization Group Optimized Perturbation

We report a recent extension of a variationally optimized perturbation method, combining it with renormalization group properties in a straightforward way. This can provide a series of approximations to nonperturbative quantities such as the chiral symmetry breaking order parameters typically. It is first illustrated with the mass gap of the O(2N) Gross-Neveu model, compared with the known exact results for arbitrary N. We then discuss application in QCD with some preliminary results for the dynamical quark mass, the pion decay constant, etc.