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Determination of the lightest strange resonance $K_0^*(700)$ or $κ$, from a dispersive data analysis

In this work we present a precise and model-independent dispersive determination from data of the existence and parameters of the lightest strange resonance $κ/K_0^*(700)$. We use both subtracted and unsubtracted partial-wave hyperbolic and fixed-$t$ dispersion relations as constraints on combined fits to $πK\rightarrowπK$ and $ππ\rightarrow K\bar K$ data. We then use the hyperbolic equations for the analytic continuation of the isospin $I=1/2$ scalar partial wave to the complex plane, in order to determine the $κ/K_0^*(700)$ and $K^*(892)$ associated pole parameters and residues.