Aug 2 – 6, 2021
Europe/Brussels timezone

Dispersive study of $K\pi$ scattering and determination of threshold parameters and of $\kappa/K_0^*(700)$ resonance properties

Aug 5, 2021, 10:50 AM


Parallel contribution B: Light quarks Parallels Track B


Jose R. Pelaez Sagredo (Universidad Complutense)


We have recently completed the coupled dispersive analysis of $\pi K$ pi pi -> K anti-K data.
We show that just fitting data fails to satisfy the dispersive representation and leads to inconsistencies with threshold sum-rules as well as unreliable resonance parameterizations.

Our main result is a set of constrained fits to data that satisfy 16 dispersion relations of different kinds and allow for a reliable extraction of threshold and subtreshold parameters to be compared with Chiral Perturbation Theory and lattice QCD. In addition, we obtain a precise dispersive determination of the controversial light kappa-meson parameters, which has therefore become a "confirmed" state in the PDG, completing the light meson scalar nonet. The constrained fits to data are easy to implement and ready for further theoretical and experimental studies.

Primary authors

Jose R. Pelaez Sagredo (Universidad Complutense) Dr Arkaitz Rodas (College of William and Mary)

Presentation materials