Further experimental studies of two-body radiative Υ decays

Continuing our studies of radiative Y decays, we report on a search for Y-->gammaeta and Y-->gammaf(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 gammaeta search the three decays of the eta meson to pi(+)pi(-)pi(0), pi(0)pi(0)pi(0), and gammagamma were investigated. We found no candidate events in the (3pi)(0) modes and no significant excess over expected backgrounds in the gammagamma mode to set a limit on the branching fraction of B(Y-->gammaeta)<2.1x10(-5) at 90% C.L. The three charged two-body final states h (h) over 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(Y-->gammaf(J))xB(f(J)-->h (h) over bar)similar to1.5x10(-5) have been set for each of these modes. We compare our results to measurements of other radiative Y decays, to measurements of radiative J/psi decays, and to theoretical predictions.