Three-body charmed baryon Decays with SU(3) flavor symmetry

We study the three-body anti-triplet ${\bf B_c}\to {\bf B_n}MM'$ decays with the $SU(3)$ flavor ($SU(3)_f$) symmetry, where ${\bf B_c}$ denotes the charmed baryon anti-triplet of $(\Xi_c^0,-\Xi_c^+,\Lambda_c^+)$, and ${\bf B_n}$ and $M(M')$ represent baryon and meson octets, respectively. By considering only the S-wave $MM'$-pair contributions without resonance effects, the decays of ${\bf B_c}\to {\bf B_n}MM'$ can be decomposed into irreducible forms with 11 parameters under $SU(3)_f$, which are fitted by the 14 existing data, resulting in a reasonable value of $\chi^2/d.o.f=2.8$ for the fit. Consequently, we find that the triangle sum rule of ${\cal A}(\Lambda_c^+\to n\bar K^0 \pi^+)-{\cal A}(\Lambda_c^+\to pK^- \pi^+)-\sqrt 2 {\cal A}(\Lambda_c^+\to p\bar K^0 \pi^0)=0$ given by the isospin symmetry holds under $SU(3)_f$, where ${\cal A}$ stands for the decay amplitude. In addition, we predict that ${\cal B}(\Lambda_c^+\to n \pi^{+} \bar{K}^{0})=(0.9\pm 0.8)\times 10^{-2}$, which is $3-4$ times smaller than the BESIII observation, indicating the existence of the resonant states. For the to-be-observed ${\bf B_c}\to {\bf B_n}MM'$ decays, we compute the branching fractions with the $SU(3)_f$ amplitudes to be compared to the BESIII and LHCb measurements in the future.