Observation of meson resonances in electroproduction

We observe an enhancement in the four-pion state ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ at 1.8-${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^2$ effective mass in electroproduction. Indications of enhancements in the $K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$ state are also observed near 1.8, 2.1, and 2.5 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^2$. We compare these observations with others in photoproduction and $e^{+}{e}^{-}$ annihilation.