Observation of a new Ds meson decaying to DK at a mass of 2.86 GeV/c2

We observe a new D-s meson with mass (2856.6 +/- 1.5(stat)+/- 5.0(syst)) MeV/c(2) and width (48 +/- 7(stat)+/- 10(syst)) MeV/c(2) decaying into (DK+)-K-0 and (D+KS0). In the same mass distributions, we also observe a broad structure with mass (2688 +/- 4(stat)+/- 3(syst)) MeV/c(2) and width (112 +/- 7(stat)+/- 36(syst)) MeV/c(2). To obtain this result, we use 240 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.