Analysis of ${\mathrm{\Sigma }}^{\ast }$ via isospin selective reaction $K_{L}p\to {\pi }^{+}{\mathrm{\Sigma }}^0$

The isospin-selective reaction $K_{L}p\to {\pi }^{+}{\mathrm{\Sigma }}^0$ provides a clean probe for investigating $I=1$ ${\mathrm{\Sigma }}^{\ast }$ resonances. In this work, we perform an analysis of this reaction using an effective Lagrangian approach for the first time, incorporating the well-established $\mathrm{\Sigma }(1189)1\mathrm{/}{2}^{+}$, $\mathrm{\Sigma }(1385)3\mathrm{/}{2}^{+}$, $\mathrm{\Sigma }(1670)3\mathrm{/}{2}^{-}$, $\mathrm{\Sigma }(1775)5\mathrm{/}{2}^{-}$ states, while also exploring contributions from other unestablished states. By fitting the available differential cross section and recoil polarization data, adhering to partial-wave phase conventions same as PDG, we find that besides the established resonances, contributions from $\mathrm{\Sigma }(1660)1\mathrm{/}{2}^{+}$, $\mathrm{\Sigma }(1580)3\mathrm{/}{2}^{-}$ and a ${\mathrm{\Sigma }}^{\ast }(1\mathrm{/}{2}^{-})$ improve the description. Notably, a ${\mathrm{\Sigma }}^{\ast }(1\mathrm{/}{2}^{-})$ resonance with mass around 1.54 GeV, consistent with $\mathrm{\Sigma }(1620)1\mathrm{/}{2}^{-}$, is found to be essential for describing the data in this channel, a stronger indication than found in previous analyses focusing on $\pi \mathrm{\Lambda }$ final states. While providing complementary support for $\mathrm{\Sigma }(1660)1\mathrm{/}{2}^{+}$ and $\mathrm{\Sigma }(1580)3\mathrm{/}{2}^{-}$, our results highlight the importance of the $\mathrm{\Sigma }(1620)1\mathrm{/}{2}^{-}$ region in $K_{L}p\to {\pi }^{+}{\mathrm{\Sigma }}^0$. Future high-precision measurements are needed to solidify these findings and further constrain the ${\mathrm{\Sigma }}^{\ast }$ spectrum.