Rho-omega mixing and the pion form factor in the timelike region

We determine the magnitude, phase, and $s$ dependence of $\rho$-$\omega$ “mixing” in the pion form factor in the timelike region through fits to $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\rho$ resonance, are small. The systematic errors in the $\rho$ mass and width, however, are larger than previously estimated.