Two states for the $\Xi(1820)$ resonance

TL;DR

This paper discusses the prediction of two states for the $ ext{Xi}(1820)$ resonance with different widths using the chiral unitary approach and explains recent experimental data by considering both states.

Contribution

It introduces the concept of two $ ext{Xi}(1820)$ states with distinct widths and explains recent experimental observations through this dual-state framework.

Findings

Prediction of two $ ext{Xi}(1820)$ states with different widths

Reconciliation of experimental data with theoretical predictions

Natural explanation for the large width observed in BESIII data

Abstract

We recall that the chiral unitary approach for the interaction of pseudoscalar mesons with the baryons of the decuplet predicts two states for the $\Xi(1820)$ 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 $K^- \Lambda$ mass distribution in the $\psi(3686)$ decay to $K^- \Lambda \bar\Xi^+ $, which demands a width much larger than the average of the PDG, and show how the consideration of the two $\Xi(1820)$ states provides a natural explanation to this apparent contradiction.