The role of non-abelian anomalies and gauge invariance for the effective lagrangian of vector mesons

Abstract

We note that gauge invariance, the Wess-Zumino term and the functional Legendre transform fixes almost uniquely the effective lagrangian for the π, ϱ, ω, A 1 system. It is shown that the only free parameters in L eff are ⨍ π , m ϱ 2, g ϱππ (and eventually α = ( fg/ m ϱ ) 2). Some phenomenological implications of the flavor anomalies are discussed; in particular a recent analysis on the status of the KSFR sum rule, the m A 1 2 = 2 m ϱ 2 relation and the ω → 3 π contact term are critically revisited.