Three-Body Decay of ${\Lambda }_c^{\ast }(2595)$ and ${\Lambda }_c^{\ast }(2625)$ with the Inclusion of Direct Two-Pion Coupling

Abstract

We investigate the three-body decays of ${\Lambda }_c^{\ast }(2595)$ and ${\Lambda }_c^{\ast }(2625)$ into ${\Lambda }_c\pi \pi$ by including a direct process going through the two-pion coupling of ${\Lambda }_c^{\ast }{\Lambda }_c\pi \pi$ in addition to the sequential processes going through ${\Sigma }_c(2455)$ and ${\Sigma }_c^{\ast }(2520)$. The strength of the direct coupling is related to that of the Yukawa coupling by the chiral partner structure between ${\Lambda }_c$'s and ${\Sigma }_c$'s, while the strength of the Yukawa coupling is estimated by the quark model. It is found that the direct process gives a considerable contribution especially in the decay of ${\Lambda }_c^{\ast }(2625)$. A clear indication of the direct process is seen in an asymmetric pattern in the angular correlation between the two pions. We discuss the usefulness of the detailed analysis of the decays for the study of the structure of ${\Lambda }_c^{\ast }$.

Comments: 11 pages, 15 figures