Quark Schwinger-Dyson evaluation of the l(1),l(2) coefficients in the chiral Lagrangian

Abstract

Using a systematic expansion of the quark-antiquark Bethe Salpeter wave functions in the relativistic quark model and working to O(P-4) in the chiral limit, we are able to derive theoretical expressions relating the coefficients of the chiral Lagrangian l(1),l(2) to the underlying quark-antiquark wave functions and interaction kernels. This is accomplished by using a novel technique based on a Ward identity for the quark-antiquark ladder kernel which greatly simplifies the required effort. Numerical evaluations are performed in two simple specific models.