${\chi }_{c0}$ production in $\bar{\Lambda }n$ scattering process

Abstract

In the present work, we investigate the production of ${\chi }_{c0}$ in the $\bar{\Lambda }n\to {\chi }_{c0}{K}_S^0$ process by utilizing an effective Lagrangian approach. Based on the ${\chi }_{c0}\to n{K}_S^0\bar{\Lambda }$ decay observed by the BESIII Collaboration, the coupling constants are determined by fitting the $M_{K_S^0\bar{\Lambda }}$ and $M_{n{K}_S^0}$ invariant mass spectra, where eight $N$ and $\Lambda$ state are considered. Moreover, the parameters $\beta$ is taken to be 1, 2, 3 as special cases to check the parameter dependence. Our results show that two clear structures can be observed in both $M_{K_S^0\bar{\Lambda }}$ and $M_{n{K}_S^0}$ invariant mass spectra, which should correspond to $N(1720)/N(1895)$ and $\Lambda (1600)/\Lambda (1890)$, respectively. In addition, the contributions from $N(938)$ and $\Lambda (1116)$ intermediate states are much smaller than those of the above-threshold resonances. With the fitted parameters for $\beta =1$, 2, 3, the cross sections for $\bar{\Lambda }n\to {\chi }_{c0}{K}_S^0$ are estimated to be 1.9 nb, 4.2 nb, and 8.0 nb at $\sqrt{s}=6$ GeV, respectively. Furthermore, our estimations indicate that the differential cross sections for $\bar{\Lambda }n\to {\chi }_{c0}{K}_S^0$ reach a maximum in the forward angle region.