Strong Decays of observed ${\Lambda }_c$ Baryons in the ${}^3{P}_0$ Model

Abstract

The strong decay widths and some important branching ratios of possible Okubo-Zweig-Iizuka(OZI)-allowed strong decay channels of ${\Lambda }_c(2595{)}^{+}$, ${\Lambda }_c(2625{)}^{+}$, ${\Lambda }_c(2765{)}^{+}$ (${\Sigma }_c(2765{)}^{+}$), ${\Lambda }_c(2860{)}^{+}$, ${\Lambda }_c(2880{)}^{+}$ and ${\Lambda }_c(2940{)}^{+}$ are computed in a ${}^3{P}_0$ model, and possible assignments of these ${\Lambda }_c$ are given. (1), ${\Lambda }_c(2595{)}^{+}$ and ${\Lambda }_c(2625{)}^{+}$ are possibly the $1P$-wave charmed baryons ${\Lambda }_{c1}({\frac{1}{2}}^{-})$ and ${\Lambda }_{c1}({\frac{3}{2}}^{-})$, respectively. (2), ${\Lambda }_c(2765{)}^{+}$ (${\Sigma }_c(2765{)}^{+}$) seems impossibly the $1P$-wave ${\Lambda }_c$, it could be the $2S$-wave or $1D$-wave charmed baryon. So far, the experimental information has not been sufficient for its identification. (3), ${\Lambda }_c(2860{)}^{+}$ seems impossibly $2S$-wave charmed baryon, it may be the $P$-wave ${\tilde{\Lambda }}_{c2}^{}({\frac{3}{2}}^{-})$ or ${\tilde{\Lambda }}_{c2}^{}({\frac{5}{2}}^{-})$, it could also be the $D$-wave ${\check{\Lambda }}_{c1}^2({\frac{1}{2}}^{+})$ or ${\check{\Lambda }}_{c1}^2({\frac{3}{2}}^{+})$. If the hypothesis that ${\Lambda }_c(2860{)}^{+}$ has $J^P={\frac{3}{2}}^{+}$ is true, ${\Lambda }_c(2860{)}^{+}$ is possibly the $D$-wave ${\check{\Lambda }}_{c1}^2({\frac{3}{2}}^{+})$ which has a predicted branching ratio $R=\Gamma ({\Sigma }_c(2520)\pi )/\Gamma ({\Sigma }_c(2455)\pi )=2.8$. (4), ${\Lambda }_c(2880{)}^{+}$ is impossibly a $1P$-wave or $2S$-wave charmed baryon, it may be a $D$-wave ${\check{\Lambda }}_{c3}^2({\frac{5}{2}}^{+})$ with ${\Gamma }_{total}=1.3$ MeV. The predicted branching ratio $R=\Gamma ({\Sigma }_c(2520)\pi )/\Gamma ({\Sigma }_c(2455)\pi )=0.35$, which is consistent with experiment. (5), ${\Lambda }_c(2940{)}^{+}$ is the $P$-wave ${\tilde{\Lambda }}_{c2}^{}({\frac{3}{2}}^{-})$ or ${\tilde{\Lambda }}_{c2}^{}({\frac{5}{2}}^{-})$, it is also possibly the $D$-wave ${\check{\Lambda }}_{c3}^2({\frac{5}{2}}^{+})$ or ${\check{\Lambda }}_{c3}^2({\frac{7}{2}}^{+})$.

Comments: 13 pages, 2 figures, 17 tables, RevTex