Identification of a Pseudoscalar State at 1440 MeV 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

From a partial-wave analysis of the $K\overline{K}\ensuremath{\pi}$ system in the decay $\frac{J}{\ensuremath{\psi}}\ensuremath{\rightarrow}\ensuremath{\gamma}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$, it is determined that the quantum numbers of the $K\overline{K}\ensuremath{\pi}$ resonance at 1440 MeV, previously identified as the $E(1420)$, are ${J}^{\mathrm{PC}}={0}^{\ensuremath{-}+}$. This new particle has been named the $\ensuremath{\iota}$.