Penta-quark States with Strangeness, Hidden Charm and Beauty

TL;DR

This paper discusses the necessity of unquenched multi-quark models to explain baryon spectra, predicts new hyperon and super-heavy resonances with hidden charm and beauty, and highlights recent experimental hints of such states.

Contribution

It introduces a multi-quark dynamic framework to explain baryon excited states and predicts new hyperon and super-heavy resonances with hidden charm and beauty.

Findings

Evidence suggests unquenched multi-quark effects are essential.

Predicted hyperon excited states with strangeness, charm, and beauty.

Recent LHCb hints support the existence of hidden charm penta-quark states.

Abstract

The classical quenched quark models with three constituent quarks provide a good description for the baryon spatial ground states, but fail to reproduce the spectrum of baryon excited states. More and more evidences suggest that unquenched effects with multi-quark dynamics are necessary ingredients to solve the problem. Several new hyperon resonances reported recently could fit in the picture of penta-quark states. Based on this picture, some new hyperon excited states were predicted to exist; meanwhile with extension from strangeness to charm and beauty, super-heavy narrow $N^*$ and $\Lambda^*$ resonances with hidden charm or beauty were predicted to be around 4.3 and 11 GeV, respectively. Recently, two of such $N^*$ with hidden charm might have been observed by the LHCb experiment. More of those states are expected to be observed in near future. This opens a new window in order to study hadronic dynamics for the multi-quark states.