A Relativistic Description of Hadronic Decays of the Meson $\pi_{1}$
  The subject of this work is the analysis of hadronic decays of the exotic meson $\pi_{1}$ in a fully relativistic formalism, and comparison with the nonrelativistic results. The relativistic spin wave functions of mesons and hybrids are constructed based on unitary representations of the Lorentz group. The radial wave functions are obtained from phenomenological considerations of the mass operator. We find that the decay channels $\pi b_{1}$ and $\pi f_{1}$ are favored, in agreement with the results obtained using other models, thus indicating some model independence of the S+P selection rules. 
Nikodem J. Poplawski