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

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.

Comments: 9 pages, 3 figures