Exclusive radiative Υ(1S) decays

Abstract
We have searched for radiative decays of the Υ(1S) resonance, Υ(1S)→γX, where X decays into two oppositely charged pions, kaons, or protons. Not finding any such decays, upper limits on branching fractions are calculated. These limits are compared to measured branching fractions in radiative J/ψ decays, and to theoretical predictions.