  Symmetrization selection rules for the decay of four-quark states to two J=0
mesons are analysed in a non - field theoretic context with isospin symmetry.
The OZI allowed decay of an isoscalar J^PC = (1,3,...)^{-+} exotic state to
eta' eta or f_0' f_0 is only allowed for four-quark components of the state
containing one s sbar pair, providing a filter for strangeness content in these
states. Decays of four-quark a_0 states are narrower than otherwise expected.
If the experimentally observed 1^{-+} enhancement in eta pi is resonant, it is
qualitatively in agreement with being a four-quark state.

High Energy Physics - Phenomenology