Measurement of the $e^{+}e^{-}\rightarrowηπ^{+}π^{-}$ cross section with the CMD-3 detector at the VEPP-2000 collider
hep-ex
/ Authors
S. S. Gribanov, A. S. Popov, R. R. Akhmetshin, A. N. Amirkhanov, A. V. Anisenkov, V. M. Aulchenko, V. Sh. Banzarov, N. S. Bashtovoy, D. E. Berkaev, A. E. Bondar
and 50 more authors
A. V. Bragin, S. I. Eidelman, D. A. Epifanov, L. B. Epshteyn, A. L. Erofeev, G. V. Fedotovich, S. E. Gayazov, F. J. Grancagnolo, A. A. Grebenuk, D. N. Grigoriev, F. V. Ignatov, V. L. Ivanov, S. V. Karpov, V. F. Kazanin, A. N. Kirpotin, I. A. Koop, A. A. Korobov, O. A. Kovalenko, A. N. Kozyrev, E. A. Kozyrev, P. P. Krokovny, A. E. Kuzmenko, A. S. Kuzmin
/ Abstract
The cross section of the process $e^{+}e^{-}\rightarrowηπ^{+}π^{-}$ 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 $η\rightarrowγγ$ is used for $η$ meson reconstruction in the data sample corresponding to an integrated luminosity of $78.3$ pb$^{-1}$. The energy dependence of the $e^{+}e^{-}\rightarrowηπ^{+}π^{-}$ cross section is fitted within the framework of vector meson dominance in order to extract the $Γ(ρ(1450)\rightarrow{^{+}e^{-}})\mathcal{B}(ρ(1450)\rightarrowηπ^{+}π^{-})$ and the $Γ(ρ(1700)\rightarrow{e^{+}e^{-}})\mathcal{B}(ρ(1700)\rightarrowηπ^{+}π^{-})$ products. Based on conservation of vector current, the analysed data are used to test the relationship between the $e^{+}e^{-}\rightarrowηπ^{+}π^{-}$ cross section and the spectral function in $τ^-\rightarrowηπ^-π^0ν_τ$ decay. The $e^{+}e^{-}\rightarrowηπ^{+}π^{-}$ cross section measured with the CMD-$3$ detector is in good agreement with the previous measurements.