Speaker
Description
The chiral unitary approach produces two states from the pseudoscalar-baryon decuplet interaction in the region of the $ \Xi(1820)$. A recent BESIII experiment on the $ \Psi(3868) \to \bar \Xi K^- \Lambda$ showed a clean peak that had an abnormally large width and was interpreted in [1] in terms of the two $\Xi(1820)$. In view of this, we propose to look at the $\Omega_c \to \pi^+ \, (\pi^0,\, \eta)\, \pi \Xi^*$ reaction [2], where the $\pi \Xi^*$ invariant mass shows an interference pattern of the two resonances. A third reaction $\Psi(3686) \to \bar Ξ^+ \bar K^0 Σ^{∗−}$ [3] looks at the $\bar K^0 Σ^∗$ invariant mass distribution, where due to phase space restrictions, the lower mass $ \Xi(1820)$ is suppressed and the higher mass around 1875 MeV with a larger width shows up clearly.
[1] R.~Molina, W.~H.~Liang, C.~W.~Xiao, Z.~F.~Sun and E.~Oset,
%``Two states for the $\Xi(1820)$ resonance,''
[arXiv:2309.03618 [hep-ph]].
[2] W.~H.~Liang, R.~Molina and E.~Oset,
%``The $\Omega_c \to \pi^+ \, (\pi^0,\, \eta)\, \pi \Xi^*$ reactions and the two $\Xi(1820)$ states,''
[arXiv:2404.18882 [hep-ph]].
[3] Man-Yu Duan, Jing Song, Wei-Hong Liang and E. Oset
Searching for the two poles of the Ξ(1820) in the $\Psi(3686) \to \bar Ξ^+ \bar K^0 Σ^{∗−}$ decay
to be submitted.
