Decays of Roper-like singly heavy baryons in a chiral model

Abstract

We present a chiral model describing decays of the Roper-like $\Lambda_c(2765)$ and $\Xi_c(2970)$ as well as those of the heavy quark spin-doublet $\{\Sigma_c(2455),\Sigma_c(2520)\}$ and $\{\Xi_c',\Xi_c(2645)\}$, by focusing on chiral representations of diquarks inside the heavy baryons. Based on our chiral model together with the heavy quark spin symmetry, we derive a relation satisfied by axial charges of the heavy baryons that controls magnitude of their one pion (kaon) decays. Besides, it is shown that the large decay widths of the Roper-like $\Lambda_c(2765)$ and $\Xi_c(2970)$, which cannot be implemented by conventional non-relativistic quark models, are explained by reasonable values of the axial charges. In addition, we apply the chiral model to bottom baryons and predict decay widths of the undiscovered Roper-like $\Xi_b$. We expect that our present investigation leads to elucidation of dynamical properties of the excited heavy baryons from the viewpoint of chiral symmetry.