 Three-quark flavour singlet

The antisymmetric flavour representation ${\bigwedge }^{3}3$ has dimension one and consists of the alternating $uds$ combination. Its sole weight is $(I_3,Y)=(0,0)$, distinct as a representation from the octet $\Lambda$ at the same weight. The Pauli constraint on three-quark flavour multiplets requires orbital excitation for a three-quark colour-singlet realization.