Description of the newly observed ${\Omega }_c^{\ast }$ states as molecular states

Abstract

In this work, we study the strong decays of the newly observed ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ assuming that ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ as $S$-wave $D\Xi$ and $D^{\ast }\Xi$ molecular state, respectively. Since the ${\Omega }_c^{\ast }$ was observed in the ${\Xi }_c^{+}{K}^{-}$ invariant mass distributions, the partial decay width of ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ into ${\Xi }_c^{+}{K}^{-}$ through hadronic loops are evaluated with the help of the effective Lagrangians. Moreover, the decay channel of ${\Xi }_c^{{}^{\prime }}\bar{K}$ is also included. The decay process is described by the $t$-channel $\Lambda$, $\Sigma$ baryons and $D_s$, $D_s^{\ast }$ mesons exchanges, respectively. By comparison with the LHCb observation, the current results support the ${\Omega }_c^{\ast }(3327)$ with$J^P=3/2^{-}$ as pure $D^{\ast }\Xi$ molecule while the ${\Omega }_c^{\ast }(3327)$ with $J^P=1/2^{-}$ can not be well reproduced in the molecular state picture. In addition, the spin-parity $J^P=1/2^{-}$ $D\Xi$ molecular assumptions for the ${\Omega }_c^{\ast }(3185)$ can't be conclusively determined. It may be a meson-baryon molecule with a big $D\Xi$ component. Although the decay width of the ${\Omega }_c^{\ast }\to \bar{K}{\Xi }_c^{{}^{\prime }}$ is of the order several MeV, it can be well employed to test the molecule interpretations of ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$.