Final-state interactions and s-quark helicity conservation in B → J/ψK∗

The recent BaBar measurement has confirmed substantial strong phases for the B → J/ψK∗ decay amplitudes implying violation of factorization in this decay mode. In the absence of polarization measurement of a lepton pair from J/ψ, however, the relative phases of the spin amplitudes still have a twofold ambiguity. In one set of the allowed phases the s-quark helicity conserves approximately despite final-state interactions. In the other set, the s-quark helicity is badly violated by long-distance interactions. We cannot rule out the latter since validity of perturbative QCD is questionable for this decay. We examine the large final-state interactions with a statistical model. Toward resolution of the ambiguity without lepton polarization measurement, we discuss relevance of other B → 1−1− decay modes that involve the same feature. PACS 13.20.He, 12.40.Ee, 12.39.Ki, 12.15.Ji Typeset using REVTEX