Evidence for a Narrow Massive State in the Radiative Decays of the Upsilon*

Evidence is presented for a state, which we call <, with a mass M = (8322 f 8 f 24) MeV and a line width < 80 MeV (90% confidence level) using the Crystal Ball NaI(T1) detector at DORIS II. Radiative transitions to this state are observed from about 100,000 Y(1S) decays in two independent sets of data: one in which < --* multiple hadrons, and one which is strongly biased towards < --) 2 low multiplicity jets. The branching ratio to this state from Y(lS) is on the order of 0.5% . Presented at the 12th SLAC Summer Institute on Particle Physics Stanford, California, July 22 August 3, 1984 * Work supported by the Department of Energy, contract DE-AC03-76SFOO515 t Permanent address: Institute of Nuclear Physics, Cracow, Poland. 0 Boguslaw B. Niczyporuk 1984