Abstract :
We show that current experimental data indicate that the strong decay mode π2 → b1π is anomalously small (more than 3 times smaller than all other decay modes of the π2. This acts as a powerful discriminator for and against various decay models. Non-relativistic quark models with spin-1 pair creation, e.g. 3P0 (flux-tube breaking) and 3S1 and 3D1 (chromo-electric string-breaking) models, as well as lowest order one-boson (in this case π) emission models, can accommodate the experimental data because of a quark-spin selection rule. Models that violate the selection rule, e.g. higher order one-boson emisson decay mechanisms, as well as mixing with other Fock states and relativistic effects, may be constrained by the small π2 → b1π decay.
