Brodzicka, J (reprint author), KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki, Japan.
We report the observation of a new D(sJ) meson produced in B(+)->(D) over bar (0)D(sJ)->(D) over bar (0)D(0)K(+). This state has a mass of M=2708 +/- 9(-10)(+11) MeV/c(2), a width Gamma=108 +/- 23(-31)(+36) MeV/c(2) and a 1(-) spin-parity. The statistical significance of this observation is 8.4 sigma. The results are based on an analysis of 449x10(6) B (B) over bar events collected at the Gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.