Is pentaquark doublet a hadronic molecule?

Abstract

A recently announced discovery by LHCb of a doublet of overlapping pentaquark resonances poses a question of what can be the origin of this doublet structure. We attract attention to the fact that such degeneracy could naturally arise if constituent "baryon" and "meson" were in the colored rather than colorless states. This is an appealing possibility, also because in such a case the pentaquark state would be no less "elementary" than the other hadrons, and would provide a chance for essentially new non-Abelian chemistry.