Production of $\ddot{I}ƒ$ in $\ddot{I}ˆ(2S)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ$

Abstract

Using 14M $\ddot{I}ˆ(2S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $\ddot{I}ˆ(2S)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ,J/\ddot{I}ˆ\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}$. The $\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ mass spectrum, distinctly different from phase space, suggests $\ddot{I}ƒ$ production in this process. Two different theoretical schemes are used in the global fit to the data. The results are consistent with the existence of the $\ddot{I}ƒ$. The $\ddot{I}ƒ$ pole position is determined to be $(552_{-106}^{+84})-i(232_{-72}^{+81})$ MeV/$c^2$.

9 pages, 11 figures. Accepted by Phys. Lett. B