Baryon states with hidden charm in the extended local hidden gauge approach

Abstract

The s-wave interaction of $\bar{D}{\Lambda }_c,\bar{D}{\Sigma }_c,\bar{D}{\Lambda }_c,\bar{D}{}^{\ast }{\Sigma }_c$ and $\bar{D}{\Sigma }_c^{\ast },\bar{D}{}^{\ast }{\Sigma }_c^{\ast }$, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of $\bar{D}{\Sigma }_c$ - $\bar{D}{}^{\ast }{\Sigma }_c$ with $J^P=1/2^{-}$, and two of $\bar{D}{\Sigma }_c^{\ast }$ - $\bar{D}{}^{\ast }{\Sigma }_c^{\ast }$ with $J^P=3/2^{-}$. Moreover, we find a $\bar{D}{}^{\ast }{\Sigma }_c$ resonance which couples to the $\bar{D}{\Lambda }_c$ channel and one spin degenerated bound state of $\bar{D}{}^{\ast }{\Sigma }_c^{\ast }$ with $J^P=1/2^{-},5/2^{-}$.

Comments: 24 pages, 6 figures