Search for the Low-Lying Excited Baryon Σ^*(1/2⁻) through Process ${\Lambda }_{\mathrm{c}}^{+}\to \Lambda K^0{\pi }^{+}$

Abstract Motivated by recent BESIII measurements of the singly Cabibbo-suppressed processes ${\Lambda }_{\mathrm{c}}^{+}\to \Lambda K^{+}{\pi }^0$ and ${\Lambda }_{\mathrm{c}}^{+}\to \Lambda K_{\mathrm{S}}^0{\pi }^{+}$, we investigate the process ${\Lambda }_{\mathrm{c}}^{+}\to \Lambda K^0{\pi }^{+}$ by taking into account the contribution from the low-lying excited baryon Σ^*(1/2⁻), dynamically generated via the S-wave pseudoscalar meson-octet baryon interaction, as well as from the intermediate resonances K^*(892) and N (1535). Our model successfully reproduces the BESIII π⁺K⁰ invariant mass distribution, and predicts a distinct cusp structure around 1.43 GeV in the π⁺Λ invariant mass distribution, which is associated with the predicted Σ^*(1/2⁻). Future high-precise measurements of this process at BESIII, Belle II, and the proposed Super Tau-Charm Facility experiments will be crucial for testing the existence of Σ^*(1/2⁻) and advancing our understanding of the light baryon spectrum.