Study $\Xi_c^+ \to \Lambda {\bar{K}}^0 \pi^+$ and search for the low-lying baryons $\Xi(1/2^-)$ and $\Sigma(1/2^-)$

Abstract

Since searches for the low-lying excited baryons $\Xi(1/2^-)$ and $\Sigma(1/2^-)$ are crucial to deepening our understanding of the light baryon spectrum, we have investigated the Cabibbo-favored process $\Xi_c^+ \to \Lambda {\bar{K}}^0 \pi^+$ by taking into account the $S$-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach, which could dynamically generate the resonances $\Xi(1/2^-)$ and $\Sigma(1/2^-)$. The contributions from the excited kaons are double Cabibbo-suppressed, and the contribution from the $\Sigma(1385)$ is also suppressed due to Korner-Pati-Woo theory, thus those states are expected to play negligible contributions in this process. We have predicted the $\bar{K}^0 \Lambda$ and $\pi^+\Lambda$ invariant mass distributions, which have the clear signals of the $\Xi(1/2^-)$ and $\Sigma(1/2^-)$. Thus, the $\Xi_c^+ \to \Lambda {\bar{K}}^0 \pi^+$ is an ideal process to search for the low-lying baryons $\Xi(1/2^-)$ and $\Sigma(1/2^-)$, and we make a call for a precise measurements of this process in experiments, such as Belle II, LHCb, and the proposed Super Tau-Charm Facility (STCF).