Interpretation of $Ω(2012)$ as a $Ξ(1530)K$ molecular state

Abstract

We investigate the mass and strong decay properties of the $Ω(2012)$ resonance using QCD sum rules, assuming it to be an S-wave $Ξ(1530)\bar{K}$ molecular pentaquark state with $I(J^{P})= 0(\frac{3}{2}^{-})$. A unified interpolating current is constructed, and the two-point correlation functions and three-point functions are calculated up to dimension-13 and 10 condensate terms in the OPE series, respectively. The negative-parity contribution is isolated by employing parity-projected sum rules. The two-body strong decays to $Ξ^0 K^-$ and $Ξ^- \bar{K}^0$ are studied via their three-point correlation functions. Our analysis yields a mass of $2.00 \pm 0.15~\mathrm{GeV}$ and a total two-body decay width of $Γ= 0.96^{+0.79}_{-0.41}~\mathrm{MeV}$ for the $Ξ(1530)\bar{K}$ molecular state. The ratio of the two-body decay branching fractions is obtained as $\mathcal{R}^{Ξ^- \bar{K}^0}_{Ξ^0 K^-} = 0.85$. These results are compatible with the experimental data for the $Ω(2012)$ within uncertainties and support its interpretation as a $Ξ(1530)\bar{K}$ molecular pentaquark state.