Observation of a NewDsMeson Decaying toDKat a Mass of2.86GeV/c2

We observe a new $D_s$ meson with mass $(2856.6\pm {1.5}_{\mathrm{stat}}\pm {5.0}_{\mathrm{syst}})\mathrm{MeV}/c^2$ and width $(48\pm 7_{\mathrm{stat}}\pm {10}_{\mathrm{syst}})\mathrm{MeV}/c^2$ decaying into $D^0{K}^{+}$ and $D^{+}{K}_S^0$. In the same mass distributions, we also observe a broad structure with mass $(2688\pm 4_{\mathrm{stat}}\pm 3_{\mathrm{syst}})\mathrm{MeV}/c^2$ and width $(112\pm 7_{\mathrm{stat}}\pm {36}_{\mathrm{syst}})\mathrm{MeV}/c^2$. To obtain this result, we use $240{\mathrm{fb}}^{-1}$ of data recorded by the BABAR detector at the PEP-II asymmetric-energy $e^{+}{e}^{-}$ storage rings at the Stanford Linear Accelerator Center running at center-of-mass energies near 10.6 GeV.