Theoretical study of $N(1535)$ and ${\Sigma }^{\ast }(1/2^{-})$ in the Cabibbo-favored process ${\Lambda }_c^{+}\to p{\bar{K}}^0\eta$

Abstract

Motivated by the recent experimental measurements, we have investigated the Cabibbo-favored process ${\Lambda }_c^{+}\to p{\bar{K}}^0\eta$, where the $N(1535)$ resonance is dynamically generated from the $S$-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach. The contributions from the intermediate $N(1650)$ and the predicted low-lying baryon ${\Sigma }^{\ast }(1/2^{-})$ are also considered. In addition, a Breit-Wigner amplitude for the $N(1535)$ resonance is checked. By comparing with the measured $\eta p$, ${\bar{K}}^0\eta$, and $p{\bar{K}}^0$ invariant mass squared distributions, our results support the interpretation of $N(1535)$ as a dynamically generated state. Furthermore, we demonstrate that, with the contribution from ${\Sigma }^{\ast }(1/2^{-})$ taken into account, the calculated invariant mass spectrum agrees with the Belle measurements. Future precise measurements of the ${\Lambda }_c^{+}\to p{\bar{K}}^0\eta$ process can further elucidate the existence of the low-lying baryon ${\Sigma }^{\ast }(1/2^{-})$.

Comments: 10 pages, 5 figures, the version of publication in PRD