Unitarity and current algebra constraints in a low-energy K$\pi$ model

A crossing-symmetric model for low-energy pi K scattering is investigated. The model satisfies elastic unitarity to a good approximation, on and off the mass shell. With some minimal additional input from current algebra, s-wave phase shift a and p-wave scattering lengths are determined. A comparison is made with further current algebra theorems including those arising from the (3*,3)+(3,3*) symmetry-breaking scheme. (14 refs).