INFRARED DIVERGENCE AND TWIST-3 WAVE FUNCTIONS IN QCD FACTORIZATION FOR B → PP DECAYS

The problem of chirally enhanced corrections for B decays into two light pseudoscalars in QCD factorization scheme is discussed. We find that the infrared divergences of the vertex corrections cancel only if the twist-3 Wave functions are symmetric. In that case chirally enhanced corrections can be included consistently. The divergences appeared in the hard spectator scattering are also discussed briefly.