Stability of hexaquarks in the string limit of confinement

The stability of systems containing six quarks or antiquarks is studied within a simple string model inspired by the strong-coupling regime of quantum chromodynamics and used previously for tetraquarks and pentaquarks. We discuss both six-quark (q⁶) and three-quark-three-antiquark (q³q¯³) states. The quarks are assumed to be distinguishable and thus not submitted to antisymmetrization. It is found that the ground state of (q⁶) is stable against dissociation into two isolated baryons. For the case of (q³q¯³), our results indicate the existence of a bound state very close to the threshold. The investigations are extended to (q³Q³) and (Q³q¯³) systems with two different constituent masses, and their stability is discussed as a function of the mass ratio.