THE CHIRAL LOOP EXPANSION OF THE NONLEPTONIC WEAK-INTERACTIONS OF MESONS

In the framework of the effective low-energy chiral lagrangian, we determine the one-loop effective action describing the strangeness-changing nonleptonic weak interactions of the pseudoscalar mesons. The effective action includes the counterterms necessary to accomodate the ultraviolet divergences arising from the loops, which we calculate. We obtain a closed expression for the regularized one-loop effective action sufficient to describe amplitudes involving up to four mesons. Finally, we discuss the observability of the tadpole caused by weak interactions. © 1990.