Abstract :
In the last decade the CLEO II collaboration, using the CESR e+e− storage ring, has accumulated nearly 15fb−1 of luminosity. in the energy region around 10.5 GeV, corresponding to the production of more than 3·107 charmed particles (apart from daughters of B meson decay). This has produced new results in the spectroscopy of charmed baryons and mesons and a much improved limit on View the MathML source mixing. We present evidence for an excitation of the Ξc, seen in both charge states; namely, the Ξ′c, the View the MathML source c{sq} state, which is symmetric under exchange of light quark quantum numbers. Another state is seen in the decays to Ξc+π+π− and Ξc0π+π− via an intermediate View the MathML source, and is consistent with the Ξc1, the View the MathML source p-wave state analogous to the Λc1+(2625). The mass differences relative to the ground state are: M(Ξc+′) − M(Ξc) = (107.8 ± 1.7 ± 2.5) MeV/c2, M(Ξc0′) − M(Ξc) = (107.0 ± 1.5 ± 2.5) MeV/c2, M(Ξc1+) − M(Ξc+) = (348.6 ± 0.6 ± 1.0) MeV/c2, and M(Ξc10) − M(Ξc0) = (347.2 ± 0.7 ± 2.0) MeV/c2. We have made the first (preliminary) measurements of the natural widths of the Σc++ and Σc0 baryons: Γ++ = (2.98−.35+.38 ± 0.5) MeV, and Γ0 = (2.63−.33+.36 ± 0.5) MeV. In the charmed meson sector we find evidence for a wide 1+ state, the D10(2460). Its mass is (2.461−.034+.041 ± .010 ± .032) GeV; its width is (290−74+101 ± 26 ± 36) MeV. We find no supporting evidence for the D∗′+, a purported radial excitation claimed by the Delphi group at a mass of (2637 ± 2 ± 6) MeV. Finally we are able, using “wrong-sign” (DCSD) Kπ decays to make the following measurements: 1) the observed ratio of DCSD decays relative to the Cabibbo-allowed rate is Rws = (0.34 ± 0.7 ± .06)%, 2) the mixing parameters are bounded, at 95% confidence, by x′2 < .001 and −.059 < y′ < .003. x′ and y′ are, in the absence of final state phase differences, the real and imaginary parts of |frsol|δM/Γ.
