The pion-kaon scattering amplitude constrained with forward dispersion   relations up to 1.6 GeV
  In this work we provide simple and precise parameterizations of the existing $\pi K$ scattering data from threshold up to 1.6 GeV, which are constrained to satisfy forward dispersion relations as well as three additional threshold sum rules. We also provide phenomenological values of the threshold parameters and of the resonance poles that appear in elastic scattering. 
J. R. Pelaez and A. Rodas (Universidad Complutense de Madrid)
hep-ph