A Relativistic Description of Hadronic Decays of the Exotic Meson   $\pi_{1}$
  Exotic mesons are striking predictions of quantum chromodynamics that go beyond the quark model. They can provide great insight into understanding phenomena such as asymptotic freedom, confinement, and dynamical symmetry breaking. This work analyzes hadronic decays of exotic mesons, with a focus on the lightest one, the $J^{PC}=1^{-+}$ $\pi_{1}$, in a fully relativistic formalism. The relativistic spin wave functions of normal and exotic mesons are constructed based on unitary representations of the Poincare group. The radial wave functions are obtained from phenomenological considerations of the mass operator. We find that fully relativistic results using Wigner rotations differ significantly from nonrelativistic ones. Moreover, the S+P selection rule is also satisfied in relativistic formalism. Final state interactions do not change these results much. 
Nikodem J. Poplawski