Toward the goal of extracting the weak angle alpha, the decay B^0/B^0-bar to a_0^{ +/-}pi^{ -/+} was recently measured. The decay B^0 to a_0^+pi^- is not only forbidden in the factorization limit of the tree interaction, but also strongly suppressed for the penguin interaction if short-distance QCD dominates. This makes extraction of alpha very difficult from a^{ +/-}\pi^{ -/+}. We examine the simlar factorization-suppressed decays, in particular, B^0\to b_1^+pi^-. The prospect of obtaining alpha is even less promising with b_1^{ +/-}pi^{ -/+}. To probe how well the short-distance dominance works, we emphasize importance of testing helicity conservation in the charmless B decays with spins.
Categories: hep-ph