Study of $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^0\bar{\mathrm{\Sigma }}{}^0$ and ${\mathrm{\Sigma }}^{+}\bar{\mathrm{\Sigma }}{}^{-}$ by Initial State Radiation Method at Belle

The processes $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^0\bar{\mathrm{\Sigma }}{}^0$ and $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^{+}\bar{\mathrm{\Sigma }}{}^{-}$ are studied using initial-state-radiation events in a sample of 980 $f{b}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The cross sections from the mass threshold to $3\mathrm{G}\mathrm{e}\mathrm{V}\text{\hspace{0.17em}⁣}\mathrm{/}{c}^2$ and the effective form factors of ${\mathrm{\Sigma }}^0$ and ${\mathrm{\Sigma }}^{+}$ are measured. In the charmonium region, we observe the decays $J\mathrm{/}\psi \to {\mathrm{\Sigma }}^0\bar{\mathrm{\Sigma }}{}^0$ and $J\mathrm{/}\psi \to {\mathrm{\Sigma }}^{+}\bar{\mathrm{\Sigma }}{}^{-}$ and determine the respective branching fractions.