Testing the molecular nature of the $\Omega (2012)$ with the $\psi (3770)\to \bar{\Omega }\bar{K}\Xi$ and $\psi (3770)\to \bar{\Omega }\bar{K}{\Xi }^{\ast }(1530)(\bar{\Omega }\bar{K}\pi \Xi )$ reactions

Abstract

We report on the reactions $\psi (3770)\to {\bar{\Omega }}^{+}\bar{K}\Xi$ and $\psi (3770)\to {\bar{\Omega }}^{+}\bar{K}{\Xi }^{\ast }(1530)({\Xi }^{\ast }(1530)\to \pi \Xi$), and calculate the mass distributions $\frac{\mathrm{d}\Gamma }{\mathrm{d}{M}_{\text{inv}}(\bar{K}\Xi )}$ and $\frac{\mathrm{d}\Gamma }{\mathrm{d}{M}_{\text{inv}}(\bar{K}{\Xi }^{\ast })}$, respectively. We obtain clear peaks corresponding to the $\Omega (2012)$. From the decay of $\psi (3770)\to {\bar{\Omega }}^{+}\bar{K}{\Xi }^{\ast }$, we also get a second, broader, peak around $2035\mathrm{MeV}$, which comes from the $\Omega (2012)$ decay to $\bar{K}{\Xi }^{\ast }$. This second peak is closely tied to the molecular picture of the $\Omega (2012)$ with the $\bar{K}{\Xi }^{\ast }(1530)$ and $\eta \Omega$ components. Its observation would provide a boost to the molecular picture of the $\Omega (2012)$.

6 pages, 5 figures;V2: new reference and footnote added;v3: discussion added, references added, version to appear in Eur.Phys.J.C