Measurement of the $e^{+}e^{-}rightarrowetapi^{+}pi^{-}$ cross section with the CMD-3 detector at the VEPP-2000 collider

The cross section of the process $e^{+}e^{-}rightarrowetapi^{+}pi^{-}$ is measured using the data collected with the CMD-$3$ detector at the VEPP-$2000$ collider in the center-of-mass energy range from $1.1$ to $2.0$ GeV. The decay mode $etarightarrowgammagamma$ is used for $eta$ meson reconstruction in the data sample corresponding to an integrated luminosity of $78.3$ pb$^{-1}$. The energy dependence of the $e^{+}e^{-}rightarrowetapi^{+}pi^{-}$ cross section is fitted within the framework of vector meson dominance in order to extract the $Gamma(rho(1450)rightarrow{^{+}e^{-}})mathcal{B}(rho(1450)rightarrowetapi^{+}pi^{-})$ and the $Gamma(rho(1700)rightarrow{e^{+}e^{-}})mathcal{B}(rho(1700)rightarrowetapi^{+}pi^{-})$ products. Based on conservation of vector current, the analysed data are used to test the relationship between the $e^{+}e^{-}rightarrowetapi^{+}pi^{-}$ cross section and the spectral function in $tau^-rightarrowetapi^-pi^0 u_tau$ decay. The $e^{+}e^{-}rightarrowetapi^{+}pi^{-}$ cross section measured with the CMD-$3$ detector is in good agreement with the previous measurements.