Υ and charm spectroscopy from ARGUS

Results are presented from a completed study of hadronic transitions between the Υ(2S) and Υ(1S) in the full available data set. The exclusive branching ratios Υ(1S) → iota/sup +/iota/sup -/ are found to be (2.42+-0.14+-0.14)% and (2.30+-0.25+-0.13)% for electron and muon pairs respectively. The existence of an excited charm meson, the D*/sup 0/(2420), is confirmed in a new independent data set, with a significance of 5.5 sigma for the combined samples. A search for the transition Σ/sub c/ → Λ/sub c/π, using four decay channels of the Λ/sub c/, yields evidence for both the Σ/sub c//sup ++/ and Σ/sub c//sup 0/. A mass splitting, Σ/sub c//sup ++/ - Σ/sub c//sup 0/, is found to be (2.5 +- 1.0) MeV/c/sup 2/