Study of the $\ddot{I}•$ decays into $\ddot{I}{€}^0\ddot{I}{€}^0{\hat{I}}^3$ and $\hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ final states

Abstract

Radiative decays of the $\ddot{I}•$ meson have been studied using a data sample of about 19 million $\ddot{I}•$ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. From selected $e^{+}{e}^{-}\to \ddot{I}{€}^0\ddot{I}{€}^0{\hat{I}}^3$ and $e^{+}{e}^{-}\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ events the following model independent results have been obtained: \par $Br(\ddot{I}•\to \ddot{I}{€}^0\ddot{I}{€}^0{\hat{I}}^3)=(0.92\pm 0.08\pm 0.06)\times 10^{-4}$ for $M_{\ddot{I}{€}^0\ddot{I}{€}^0}>700$ MeV, \par $Br(\ddot{I}•\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3)=(0.90\pm 0.24\pm 0.10)\times 10^{-4}$. It is shown that the intermediate mechanism $f_0(980){\hat{I}}^3$ dominates in the $\ddot{I}•\to \ddot{I}{€}^0\ddot{I}{€}^0{\hat{I}}^3$ decay and the corresponding branching ratio is \par $Br(\ddot{I}•\to f_0(980){\hat{I}}^3)=(2.90\pm 0.21\pm 1.54)\times 10^{-4}$. The systematic error is dominated by the possible model uncertainty. \par Using the same data sample the upper limit has been obtained for the P- and CP-violating decay of $\hat{I}\cdot$ at 90% CL: \par $Br(\hat{I}\cdot \to \ddot{I}{€}^0\ddot{I}{€}^0)<4.3\times 10^{-4}$ >.

13 pages, 6 figures, Submitted to Phys. Lett. B