Upper Limit for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mfrac><mml:mrow><mml:mi>J</mml:mi></mml:mrow><mml:mrow><mml:mi>Ψ</mml:mi></mml:mrow></mml:mfrac><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi> </mml:mi><mml:mo>+</mml:mo><mml:mi>A</mml:mi><mml:mi>x</mml:mi><mml:mi>i</mml:mi><mml:mi>o</mml:mi><mml:mi>n</mml:mi></mml:math>

A search has been made with the Crystal Ball Detector for axionlike particles in radiative $\frac{J}{\ensuremath{\Psi}}$ decays. An upper limit on the branching ratio $B(\frac{J}{\ensuremath{\Psi}}\ensuremath{\rightarrow}\ensuremath{\gamma}+a)&lt;1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ (90% C.L.) is obtained. This result holds for long-lived, noninteracting pseudoscalar or vector particles of mass less than 1 GeV. Thus, this experiment also places stringent limits on the existence of other possible light bosons such as those arising in supersymmetric theories.