Masses and decay widths of $\Xi_{c/b}$ and $\Xi^\prime_{c/b}$ baryons

Recently, we introduced an equal-spacing mass formula for heavy baryons and we predicted before detection the recent LHCb new negative parity $\Omega_b$ states in agreement with all the experimental data, masses and widths, within the experimental errors. In this article,akol after building a complete classification of the ground and the lowest excited $\Xi^{(')}_{c/b}$ states in terms of their spin, flavor and angular momentum, we extend our results to the $\Xi'_{c/b}$ belonging to the $SU(3)$ sextet (${\bf 6}$) flavour representation, and to the $\Xi_{c/b}$ states of the anti-triplet ($\bf \bar{3}$) configuration. By means of the equal-spacing mass rule and by studying the strong decays, we suggest possible assignments for the new LHCb $\Xi_{c}(2923)$, $\Xi_{c}(2939)$, and $\Xi_{c}(2965)$ states, but also for the $\Xi_{c}$'s previously reported by Belle and BABAR. Our results are compatible with the existing experimental data and they can be tested by future experiments, at LHCb and Belle, disentangling the remaining missing piece of information, {\it i.e.} the quantum numbers. Finally, a comparison is made between a three-quark and a quark-diquark description of $\Xi_c$ states.