Evidence for Two Excited ${\mathrm{\Omega }}^{-}$ Hyperons

Using $e^{+}{e}^{-}$ collision data corresponding to an integrated luminosity of 19,fb${}^{-1}$ collected by the BESIII detector at center-of-mass energies ranging from 4.13 to 4.70,GeV, we report the first evidence for a new excited ${\mathrm{\Omega }}^{-}$ hyperon, the $\mathrm{\Omega }(2109{)}^{-}$, through the process $e^{+}{e}^{-}\to \mathrm{\Omega }(2109{)}^{-}{\bar{\mathrm{\Omega }}}^{+}+c\mathrm{.}c\mathrm{.}$ with a significance of 4.1 $\sigma$. The mass and width of $\mathrm{\Omega }(2109{)}^{-}$ are measured to be $2108.5\pm {5.2}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.9}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}}\mathrm{M}\mathrm{e}\mathrm{V}\mathrm{/}{c}^2$ and $18.3\pm {16.4}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {5.7}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}}\mathrm{M}\mathrm{e}\mathrm{V}$, respectively. We also present evidence for a new production mechanism for the previously identified $\mathrm{\Omega }(2012{)}^{-}$ via the process $e^{+}{e}^{-}\to \mathrm{\Omega }(2012{)}^{-}{\bar{\mathrm{\Omega }}}^{+}+c\mathrm{.}c\mathrm{.}$ with a significance of 3.5 $\sigma$.