Quark confinement for multiquark systems: Application to fully charmed tetraquarks
Guang-Juan Wang, Makoto Oka, Daisuke Jido
Abstract
A new color basis system and confinement mechanism for multiquark systems are proposed according to the string-type picture of QCD. The color string configurations in the strong coupling QCD are implemented in the set of color basis states. The extended color Hilbert space for $QQ\overline{Q}\overline{Q}$ systems includes a ``hidden color'' state, which mixes with two-meson states $Q\overline{Q}+Q\overline{Q}$, This mixing effect leads to an attractive potential sufficient to form a bound state. We apply a realistic Hamiltonian model with the new scheme to fully charmed tetraquark states, $cc\overline{c}\overline{c}$, and find a bound and two resonant states, which could potentially correspond to the $cc\overline{c}\overline{c}$ tetraquark candidates recently observed in experiments.