Speaker
Description
The situation regarding the lightest strange resonance, the $\kappa/K_0^*(700)$ has been long debated for the last few decades, and although its existence is nowadays widely accepted, the data driven determination of its parameters is not so well known. In this talk we present a precise and model-independent determination of its pole parameters, therefore proving its existence. We use both partial-wave hyperbolic and fixed-$t$ dispersion relations as constraints on combined fits to $\pi K\rightarrow\pi K$ and $\pi\pi\rightarrow K\bar K$ data. We then use the former equations to perform the analytic continuation of the isospin $I=1/2$ partial waves to the complex plane, in order to determine the $\kappa/K_0^*(700)$ and $K^*(892)$ resonances. A comparison between our dispersive scattering lengths and Lattice QCD predictions are also performed.
