Study of the process $e^{+}{e}^{-}\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ in the energy range $\sqrt{s} = \mbox{1.05-2.00}$ GeV with the SND detector

Abstract

The process $e^{+}{e}^{-}\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ is studied in the center-of-mass energy range 1.05-2.00 GeV using data with an integrated luminosity of 94.5 pb${}^{-1}$ collected by the SND detector at the VEPP-2000 $e^{+}{e}^{-}$ collider. The $e^{+}{e}^{-}\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $\ddot{I}‰\hat{I}\cdot$ intermediate state. The measured cross section of the subprocess $e^{+}{e}^{-}\to \ddot{I}‰\hat{I}\cdot \to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ is consistent with previous measurements in the $e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^0\hat{I}\cdot$ mode. It is found, with a significance of 5.6$\ddot{I}ƒ$, that the process $e^{+}{e}^{-}\to \hat{I}\cdot \ddot{I}{€}^0{\hat{I}}^3$ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $e^{+}{e}^{-}\to a_0(1450){\hat{I}}^3$, is measured. It is found to be 15-20 pb in the wide energy range from 1.3 to 1.9 GeV.

10 pages, 6 figures, to be submitted to European Physical Journal C