Understanding the nature of $\Omega(2012)$ in a coupled-channel approach

Abstract

We perform a systematic analysis of the mass and strong decays of the $\Omega(2012)$ resonance in a coupled-channel approach of a bare three-quark state and a composite meson-baryon state. Besides the coupling of the bare state and $\Xi^* \bar K$ channel, the effective meson-baryon interactions are also included. We find a pole with mass of $2008$ MeV by solving the Bethe-Salpeter equation. The calculated decay widths and its ratios of branching fractions $\mathcal {R}_{\Xi \bar K}^{\Xi \pi \bar K}$ agree well with the new experimental measurement by Belle Collaboration. Our results suggest that both three-quark core and $\Xi^* \bar K$ channel are essential for the description of the $\Omega(2012)$ resonance. We expect that present calculations can help us to better understand the nature of $\Omega(2012)$ resonance.