Vector mesons in qq̄qq̄ systems

We discuss the vector mesons, IG(JPC)=1+(1−−) and 1−(1−+) in 10⊕10 representations, decaying into two ground-state octets. We derive a powerful selection rule, valid in the limit of flavor SU(3) symmetry. The octets considered are {π}, {ρ}, {b1}, {a1} and {a2}, labeled by the isovector state in the representation.