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arXiv · 2411.09610

One or two poles for the $\Xi(1820)$?

R. Molina·Wei-Hong Liang·Chu-Wen Xiao·Zhi-Feng Sun·E. Oset
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Abstract

In this talk, we present a new interpretation for the recently observed $\Xi(1820)$ resonance. 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.

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R. Molina, Wei-Hong Liang, Chu-Wen Xiao, Zhi-Feng Sun, E. Oset. 2024-11-14. One or two poles for the $\Xi(1820)$?. https://arxiv.org/abs/2411.09610

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