Continuing our studies of radiative Upsilon(1S) decays, we report on a search for Upsilon to gamma eta and Upsilon to gamma f_{ J}(2220) in 61.3 pb^{ -1} of e^{ +}e^{ -} data taken with the CLEO II detector at the Cornell Electron Storage Ring. For the gamma eta search the three decays of the eta meson to pi^{ +}pi^{ -}pi^{ 0}, pi^{ 0}pi^{ 0}pi^{ 0}, and gamma gamma were investigated. We found no candidate events in the two (3\pi)^{ 0} modes and no significant excess over expected backgrounds in the gamma gamma mode to set a limit on the branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{ -5} at 90% C.L. The three charged two-body final states h h-bar (h = pi^{ +}, K^{ +}, p) were investigated for f_{ J}(2220) production, with one, one, and two events found, respectively. Limits at 90% C.L. of B(\Upsilon to gamma f_{ J}) x B(f_{ J} to h h-bar) ~ 1.5 x 10^{ -5} have been set for each of these modes. We compare our results to measurements of other radiative Upsilon decays, to measurements of radiative J/psi decays, and to theoretical predictions.
Categories: hep-ex