Improved measurements of ${\chi }_{cJ}\to {\mathrm{\Sigma }}^{+}{\bar{\mathrm{\Sigma }}}^{-}$ and ${\mathrm{\Sigma }}^0{\bar{\mathrm{\Sigma }}}^0$ decays

Using a data sample of $(448.1\pm 2.9)\times {10}^6\psi (3686)$ events collected with the BESIII detector at the BEPCII collider, we present measurements of branching fractions for the decays $\chi_{cJ} \rightarrow \Sigma^+ \bar{\Sigma}^-$and$\Sigma^0 \bar{\Sigma}^0$\mathrm{.}Thedecays$\chi_{c1,2}\rightarrow \Sigma^+ \bar{\Sigma}^-$and$\Sigma^0 \bar{\Sigma}^0$areobservedforthefirsttime,andthebranchingfractionsfor$\chi_{c0}\rightarrow \Sigma^+ \bar{\Sigma}^-$and$\Sigma^0 \bar{\Sigma}^0$ decays are measured with improved precision. The branching fraction ratios between the charged and neutral modes are consistent with the prediction of isospin symmetry.