Search for the Low-Lying Excited Baryon \varSigma^*(1/2^-) through Process \varLambda^+_\rm c \to \varLambda K^0 \pi^+

Motivated by recent BESIII measurements of the singly Cabibbo-suppressed processes \varLambda^+_\rm c \to \varLambda K^+ \pi^0 and \varLambda^+_\rm c \to \varLambda K_\rm S^0 \pi^+, we investigate the process \varLambda^+_\rm c \to \varLambda K^0 \pi^+ by taking into account the contribution from the low-lying excited baryon \varSigma^*(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 \pi^+K^0 invariant mass distribution, and predicts a distinct cusp structure around 1.43\,GeV in the \pi^+\varLambda invariant mass distribution, which is associated with the predicted \varSigma^*(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 \varSigma^*(1/2^-) and advancing our understanding of the light baryon spectrum.