Observation of a Fourth Upsilon State in e+ e- Annihilations
Authors (1 total): J. Rohlf
A fourth state in the upsilon energy region has been seen in e+e- collisions at the Cornell Electron Storage Ring. A resonance is observed with a mass 1112±5 MeV above the lowest upsilon state. The 9.6-MeV rms width is greater than the 4.6-MeV energy resolution of the e+e- beams. The observed characteristics of the new state make it a likely candidate for the 43S state of the bb̅ system, lying above the threshold for the production of B mesons.