Nonleptonic weak decays of charmed baryons

Two-body nonleptonic weak decays of charmed baryons are analyzed in the framework of the pole model, which is more general and pertinent than current algebra since its use is not restricted to the soft meson limit and to the pseudoscalar-meson final state. The $s$-wave amplitudes are dominated by the ${\mathrm{½}}^{-}$ baryon resonances. Special attention is paid to the parity-violating ${\mathrm{½}}^{-}$-${\mathrm{½}}^{+}$ baryon matrix elements, which are evaluated using the MIT bag model. For definiteness, we compute the $\alpha$ asymmetry parameter and the branching ratios for the decay modes ${\Lambda }_c^{+}\to p{\overline{K}}^0\left({\overline{K}}^{*0\mathrm{}}\right)$, $\Lambda {\pi }^{+}\left({\rho }^{+}\right)$, ${\Sigma }^0{\pi }^{+}\left({\rho }^{+}\right)$, ${\Sigma }^{+}{\pi }^0\left({\rho }^0\right),p\phi$, and find a good agreement with experiment. We conclude that (i) there is no color suppression in ${\Lambda }_c^{+}\to p{\overline{K}}^0\left({\overline{K}}^{*0\mathrm{}}\right)$ and $p\phi$, (ii) nonspectator contributions are in general smaller than the factorizable ones for the decay modes which receive contributions from the factorizable diagram, and (iii) the predicted branching ratios will be too small if the wave functions of the heavy-quark bag model are employed. A comparison of our work with current algebra and other theoretical calculations is made.