Ωc→π+(π0,η)πΞ* , π+(π0,η)K¯Σ* reactions and the two Ξ(1820) states

Abstract

We have studied the Ωc→π+(π0,η)πΞ* and Ωc→π+(π0,η)K¯Σ* decays, where the final πΞ* or K¯Σ* comes from the decay of two resonances around the nominal Ξ(1820), which are generated from the interaction of coupled channels made of a pseudoscalar and a baryon of the decuplet. The πΞ* mass distributions obtained in the six different reactions studied are quite different, and we single out four of them, which are free of a tree level contribution, showing more clearly the effect of the resonances. The lower mass resonance is clearly seen as a sharp peak, but the higher mass resonance manifests itself through an interference with the lower one that leads to a dip in the mass distribution around 1850 MeV. Such a feature is similar to the dip observed in the S-wave ππ cross section around the 980 MeV coming from the interference of the f0(500) and f0(980) resonances. Its observation in coming upgrades of present facilities will shed light on the existence of these two resonances and their nature. On the other hand, when the Ωc→π+(π0,η)K¯Σ* reactions are studied, both peaks are observed. Published by the American Physical Society 2024