Reaction $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ at energies $\sqrt s\le1$ GeV

The cross section of reaction $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ is calculated for energies $0.65\le\sqrt s\le1$ GeV in the framework of the generalized hidden local symmetry model. The calculations are compared with the data of CMD-2 and BaBaR. It is shown that the inclusion of heavy isovector resonances $\rho(1450)$ and $\rho(1700)$ is necessary for reconciling calculations with the data. It is found that at $\sqrt s\approx1$ GeV the contributions of above resonances are much larger, by the factor of 30, than the $\rho(770)$ one, and are amount to a considerable fraction $\sim0.3{-}0.6$ of the latter at $\sqrt s\sim m_\rho$.