The small Kπ component in the K* wave functions

Abstract

We use a recently developed formalism which generalizes Weinberg's compositeness condition to partial waves higher than s-wave in order to determine the probability of having a Kπ component in the k* wave function. A fit is made to the Kπ phase shifts in p-wave, from where the coupling of k* to Kπ and the Kπ loop function are determined. These ingredients allow us to determine that the k* is a genuine state, different from a Kπ component, in a proportion of about 80%. © Società Italiana di Fisica / Springer-Verlag 2013.