SLAC - PUB - 6635 BNL - 60709 TECHNION - PH - 94 - 11 Feasibility of Extracting V td from Radiative B ( B S ) Decays

We use existing measurements of D − → K * 0 ρ − and B → ψ + K * , coupled with flavor independence of QCD, and with vector meson dominance to show that long distance contributions to B → ρ + γ are potentially very serious. We note that long distance (LD) contributions can be appreciably different in B − → ρ − + γ and B 0 → ρ 0 (ω) + γ. All radiative decays of B, B S are shown to be governed essentially by two LD and two short-distance (SD) hadronic entities. Separate measurements of B − → ρ − + γ, B 0 → ρ 0 (ω) + γ, along with B → K * + γ appear necessary for a meaningful extraction of V td. Measurements of B S → φ+γ and K * 0 +γ could also provide very useful consistency checks.