Hadron Spectroscopy with Strangeness

The Ξ(1820) resonance, one or two poles?

4 Apr 2024, 11:30

30m

Main building, Room 253 (University of Glasgow)

Session 5

Speaker

Raquel Molina Peralta

Description

We recall that the chiral unitary approach for the interaction of pseudoscalar mesons with the baryons of the decuplet predicts two states for the $\mathrm{\Xi }(1820)$ resonance, one with a narrow width and the other one with a large width. We contrast this fact with the recent BESIII measurement of the $K^{-}\mathrm{\Lambda }$ mass distribution in the $\psi (3686)$ decay to $K^{-}\mathrm{\Lambda }{\overline{\mathrm{\Xi }}}^{+}$, which demands a width much larger than the average of the PDG, and show how the consideration of the two $\mathrm{\Xi }(1820)$ states provides a natural explanation to this apparent contradiction. We also propose a reaction to observe the two-pole structure.

Presentation materials

hadron_glasgow.pdf