English

Strong decays of the $\Xi(1620)$ as a $\Lambda\bar{K}$ and $\Sigma\bar{K}$ molecule

High Energy Physics - Phenomenology 2020-06-12 v1 Nuclear Theory

Abstract

In this work, we study the strong decays of the newly observed Ξ(1620)0\Xi(1620)^0 assuming that it is a meson-baryon molecular state of ΛKˉ\Lambda\bar{K} and ΣKˉ\Sigma\bar{K}. We consider four possible spin-parity assignments JP=1/2±J^P=1/2^{\pm} and 3/2±3/2^{\pm} for the Ξ(1620)0\Xi(1620)^0, and evaluate its partial decay width into Ξπ\Xi\pi via hadronic loops with the help of effective Lagrangians. In comparison with the Belle data, the calculated decay width favors the spin-party assignment 1/21/2^- while the other spin-parity assignments do not yield a decay width consistent with data in the molecule picture. We find that about 52%52\%-68%68\% of the total width comes from the KˉΛ\bar{K}\Lambda channel, while the rest is provided by the KˉΣ\bar{K}\Sigma channel. As a result, both channels are important in explaining the strong decay of the Ξ(1620)0\Xi(1620)^0. This information is helpful to further understand the nature of the Ξ(1620)0\Xi(1620)^0.

Keywords

Cite

@article{arxiv.2006.06227,
  title  = {Strong decays of the $\Xi(1620)$ as a $\Lambda\bar{K}$ and $\Sigma\bar{K}$ molecule},
  author = {Yin Huang and Lisheng Geng},
  journal= {arXiv preprint arXiv:2006.06227},
  year   = {2020}
}