From Tetraquark to Hexaquark: A Systematic Study of Heavy Exotics in the Large Nc Limit

الأصل · EN

A systematic study of multiquark exotics with one or Nc-1 heavy quarks in the large Nc limit is presented. By binding a chiral soliton to a heavy meson, either a normal Nc-quark baryon or an exotic (Nc+2)-quark baryon is obtained. By replacing the heavy quark with Nc-1 heavy antiquarks, exotic (2Nc-2)-quark and 2Nc-quark mesons are obtained. When Nc = 3, they are just the normal triquark baryon Qqq, the exotic pentaquark baryon Q q q q q, tetraquark di-meson Q Q qq and the hexaquark di-baryon Q Q q qbar q q respectively. Their stabilities and decays are also discussed. In particular, it is shown that the ``heavy to heavy'' semileptonic decays are described by the Isgur--Wise form factors of the normal baryons.