Study $Ξ_c^+ \to Λ{\bar{K}}^0 π^+$ and search for the low-lying baryons $Ξ(1/2^-)$ and $Σ(1/2^-)$

Abstract

Since searches for the low-lying excited baryons $Ξ(1/2^-)$ and $Σ(1/2^-)$ are crucial to deepening our understanding of the light baryon spectrum, we have investigated the Cabibbo-favored process $Ξ_c^+ \to Λ{\bar{K}}^0 π^+$ by taking into account the $S$-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach, which could dynamically generate the resonances $Ξ(1/2^-)$ and $Σ(1/2^-)$. The contributions from the excited kaons are double Cabibbo-suppressed, and the contribution from the $Σ(1385)$ 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 $\bar{K}^0 Λ$ and $π^+Λ$ invariant mass distributions, which have the clear signals of the $Ξ(1/2^-)$ and $Σ(1/2^-)$. Thus, the $Ξ_c^+ \to Λ{\bar{K}}^0 π^+$ is an ideal process to search for the low-lying baryons $Ξ(1/2^-)$ and $Σ(1/2^-)$, 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).