  The properties of four quark cn - nbar cbar states are investigated as cn
di-quark and nbar cbar di-antiquark system in U(12)-classification scheme of
hadrons, recently proposed by us. We consider the negative-parity di-quark and
di-antiquark in ground states, which form with the ordinary positive-parity
ones the respective linear representations of chiral symmetry. The masses and
widths of ground-states are predicted by using Joint Spring Quark Model, and
the observed properties of X(3872) and Y(3940) are consistent, respectively,
with those of the JPC=1++ and 2++ states from the negative-parity di-quark and
di-antiquark. Their narrow-widths are explained from an orthogonality of spinor
wave functions. The properties of ground-state cs - sbar cbar system are also
predicted in this scheme.
