Note on Recent Measurements of the ?(1S) ???? (1S) and ?(2S) ???? (1S) Branching Ratios

Abstract

Recently published measurements of the branching ratios ?(?(1S) ???_? (1S)) and ?(?(2S) ???_? (1S)) by the CLEO Collaboration are examined in the context of a potential model that includes both relativistic and one-loop QCD corrections to the quark-antiquark interaction. The prediction for the width ? (?(1S) ???_? (1S)) is in excellent agreement with the new data, but the prediction for ? (?(2S) ???_? (1S)) is too small. In an effort to understand this discrepancy, we derive an upper bound on ? (?(2S) ???_? (1S)) and point out its experimental value saturates this bound.