Factorization and SU(2) heavy flavor symmetry forB-meson decays producing charmonium

We show that the factorization assumption in color-suppressed B meson decays is not ruled out by experimental data on B{→}K(K*)+J/{ψ}({ψ}'). The problem previously pointed out might be due to an inadequate choice of hadronic form factors. Within the Isgur-Wise SU(2) heavy flavor symmetry framework, we search for possible q² dependence of form factors that are capable of explaining simultaneously the large longitudinal polarization ρL observed in B{→}K*+J/{ψ} and the relatively small ratio of rates R_J/ψ={Γ}(B{→}K*+J/{ψ})/{Γ}(B{→}K+J/{ψ}). We find that the puzzle could be essentially understood if the A₁(q²) form factor is frankly decreasing, instead of being almost constant or increasing as commonly assumed. Of course, the possibility of understanding experimental data is not necessarily a proof of factorization.