Recently published measurements of the branching ratios β(Ψ(1S) →ƴƞс (1S)) and β(Ψ(2S) →ƴƞс (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 Г (Ψ(1S) →ƴƞс (1S)) is in excellent agreement with the new data, but the prediction for Г (Ψ(2S) →ƴƞс (1S)) is too small. In an effort to understand this discrepancy, we derive an upper bound on Г (Ψ(2S) →ƴƞс (1S)) and point out its experimental value saturates this bound.
Radford, Stanley F. and Repko, Wayne W., "Note on Recent Measurements of the Ψ(1S) →ƴƞс (1S) and Ψ(2S) →ƴƞс (1S) Branching Ratios" (2008). Physics. Paper 4.
@ 2008 The American Physical Society