Analysis of the Wilsonian effective potentials in dynamical chiral symmetry breaking - art. no. 045008

The nonperturbative renormalization group equation for the Wilsonian effect ive potential is given in a certain simple approximation scheme in order to study chiral symmetry breaking phenomena dynamically induced by strong gau ge interactions. The evolving effective potential is found to be nonanalyti c in the infrared, which indicates spontaneous generation of the fermion ma ss. It is also shown that the renormalization group equation gives the iden tical effective fermion mass with that obtained by solving the Schwinger-Dy son equation in the (improved) ladder approximation. Moreover, the introduc tion of the collective field corresponding to the fermion composite into th e theory space is found to offer an efficient method to evaluate the order parameters: the dynamical mass and the chiral condensate. The relation betw een the renormalization group equation incorporating the collective field a nd the Schwinger-Dyson equation is also clarified.