Study of the process $e^{+}{e}^{-}\to 3(\ddot{I}{€}^{+}\ddot{I}{€}^{-})\ddot{I}{€}^0$ in the C.M. Energy range 1.6--2.0 GeV with the CMD-3 detector

Abstract

The cross section of the process $e^{+}{e}^{-}\to 3(\ddot{I}{€}^{+}\ddot{I}{€}^{-})\ddot{I}{€}^0$ has been measured for the first time using a data sample of 56.7 pb${}^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^{+}{e}^{-}$ collider. 632$\pm$32 signal events have been selected in the center-of-mass energy range 1.6 -- 2.0 GeV. A study of dynamics of seven-pion production allows one to extract contributions of the dominated $2(\ddot{I}{€}^{+}\ddot{I}{€}^{-})\ddot{I}‰$ and $2(\ddot{I}{€}^{+}\ddot{I}{€}^{-})\hat{I}\cdot$ intermediate states.

13 pages, 5 figures