Phenomenology of the <VVP> Green's function within the Resonance Chiral Theory

Abstract

We analyse the odd-intrinsic-parity effective Lagrangian of QCD valid for processes involving one pseudoscalar with two vector mesons described in terms of antisymmetric tensor fields. Substantial information on the odd-intrinsic-parity couplings is obtained by constructing the vector-vector-pseudoscalar Green's three-point function, at leading order in 1/N_C, and demanding that its short-distance behaviour matches the corresponding OPE result. The QCD constraints thus enforced allow us to predict the decay amplitude omega -> pi gamma, the O(p^6) corrections to pi -> gamma gamma and the slope parameter in pi -> gamma gamma^*.