String dynamics and metastability of all-heavy tetraquarks

Abstract

Multiquark states have been advocated to explain recent experimental data in the heavy-light sector, and there are already speculations about multiquarks containing only heavy quarks and antiquarks. With a rigorous treatment of the four-body problem in current quark models, full-charm (ccc-c-) and full-beauty (bbb-b-) tetraquarks are found to be unbound. Thus their stability should rely on more subtle effects that are not included in the simple picture of constituent quarks. The case of (bcb-c-) might be more favorable if the naive color-additive model of confinement is replaced by a string-inspired interaction.