Possible $H$-like dibaryon states with heavy quarks

Abstract

Possible $H$-like dibaryon states ${\Lambda }_c{\Lambda }_c$ and ${\Lambda }_b{\Lambda }_b$ are investigated within the framework of quark delocalization color screening model. The results show that the interaction between two ${\Lambda }_c$'s is repulsive, so it cannot be bound state by itself. However, the strong attraction in ${\Sigma }_c{\Sigma }_c$ and ${\Sigma }_c^{\ast }{\Sigma }_c^{\ast }$ channels and the strong channel coupling, due to the central interaction of one-gluon-exchange and one-pion-exchange, among ${\Lambda }_c{\Lambda }_c$, ${\Sigma }_c{\Sigma }_c$ and ${\Sigma }_c^{\ast }{\Sigma }_c^{\ast }$ push the energy of system below the threshold of ${\Lambda }_c{\Lambda }_c$ by $22$ MeV. The corresponding system ${\Lambda }_b{\Lambda }_b$ has the similar properties as that of ${\Lambda }_c{\Lambda }_c$ system, and a bound state is also possible in ${\Lambda }_b{\Lambda }_b$ system.

Comments: 6 pages, 4 figures, 3 tables