Interpretation of the newly observed ${\Omega }_c^0$ resonances

Abstract

We study the charmed and bottomed doubly strange baryons within the heavy-quark-light-diquark framework. The two strange quarks are assumed to lie in $S$ wave and thus their total spin is 1. We calculate the mass spectra of the $S$ and $P$ wave orbitally excited states and find the ${\Omega }_c^0(2695)$ and ${\Omega }_c^0(2770)$ fit well as the $S$ wave states of charmed doubly strange baryons. The five newly ${\Omega }_c^0(X)$ resonances observed by the LHCb Collaboration, i.e. ${\Omega }_c^0(3000)$, ${\Omega }_c^0(3050)$, ${\Omega }_c^0(3066)$, ${\Omega }_c^0(3090)$, and ${\Omega }_c^0(3119)$, can be interpreted as the $P$ wave orbitally excited states. In heavy quark effective theory, we analyze their decays into the ${\Xi }_c^{+}{K}^{-}$ and ${\Xi }_c^{\prime +}{K}^{-}$, and point out that decays of the five P-wave ${\Omega }_c^0$ states into the ${\Xi }_c^{+}{K}^{-}$ and ${\Xi }_c^{\prime +}{K}^{-}$ are suppressed by either heavy quark symmetry or phase space. The narrowness of the five newly observed ${\Omega }_c^0(X)$ states can then be naturally interpreted with heavy quark symmetry.

Comments: 6 pages and 2 tables; To be published in Phys.Rev.D