Measurement of {\boldmath $J\mathrm{/}\psi \to \mathrm{\Xi }(1530{)}^{-}{\bar{\mathrm{\Xi }}}^{+}$} and evidence for the radiative decay {\boldmath $\mathrm{\Xi }(1530{)}^{-}\to \gamma {\mathrm{\Xi }}^{-}$}

The SU(3)-flavor violating decay $J\mathrm{/}\psi \to \mathrm{\Xi }(1530{)}^{-}{\bar{\mathrm{\Xi }}}^{+}+c\mathrm{.}c\mathrm{.}$ is studied using $(1310.6\pm 7.0)\times {10}^{6}J\mathrm{/}\psi$ events collected with the BESIII detector at BEPCII and the branching fraction is measured to be ${\cal{B}}(J/\psi\to\Xi(1530)^{-}\bar\Xi^{+}+c.c.)=(3.17\pm0.02_{\rm stat.}\pm0.08_{\rm syst.})\times10^{-4}$. This is consistent with previous measurements with an improved precision. The angular parameter for this decay is measured for the first time and is found to be $\alpha=-0.21\pm0.04_{\rm stat.}\pm0.06_{\rm syst.}$. In addition, we report evidence for the radiative decay $\mathrm{\Xi }(1530{)}^{-}\to \gamma {\mathrm{\Xi }}^{-}$ with a significance of 3.9$\sigma$, including the systematic uncertainties. The 90% confidence level upper limit on the branching fraction is determined to be $\mathcal{B}(\mathrm{\Xi }(1530{)}^{-}\to \gamma {\mathrm{\Xi }}^{-})\le 3.7$%.