Evidence for an<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>η</mml:mi><mml:mi>η</mml:mi></mml:math>Resonance in<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:math>Radiative Decays

Evidence for a new resonance $\ensuremath{\theta}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\eta}$ in the process $\frac{J}{\ensuremath{\psi}}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\eta}\ensuremath{\eta}$ is presented. The resonance parameters of the $\ensuremath{\theta}$ are $M=1640\ifmmode\pm\else\textpm\fi{}50$ MeV and $\ensuremath{\Gamma}={220}_{\ensuremath{-}70}^{+100}$ MeV. ${J}^{\mathrm{PC}}={2}^{++}$ is preferred over ${0}^{++}$.