Heavy Quarkonia Spectroscopy and Decays

The experimental status of stable bound states made out of heavy quarks is reviewed. The need for a way to deal with the non-perturbative transitions involved calls for precision measurements on one hand, and for discovery of as yet undetected states to confirm predictions on the other. In this article, recent experimental contributions to heavy quarkonia spectroscopy and decay will be reviewed, mostly from data analyzed by the BES and CLEO collaborations. The most dramatic recent discoveries include the detection of the first stable L = 2 state, and a first non-pionic hadronic transition in the Υ system, and a first measurement of χcJ → ΛΛ̄. Scans of the ψ ′ and Υ(1, 2, 3S) resonances are used to add information on partial and total decay widths.