Implication of the B→(ρ,ω)γ branching ratios for the CKM phenomenology

We study the implication of the recent measurement by the BELLE Collaboration of the averaged branching fraction B-barexp[B→(ρ,ω)γ]=(1.8+0.6-0.5±0.1)x10-6 for the CKM phenomenology. Combined with the averaged branching fraction B-barexp(B→K*γ)=(4.06±0.26)x10-5 measured earlier, this yields R-barexp[(ρ,ω)γ/K*γ]=(4.2±1.3)% for the ratio of the two branching fractions. Updating earlier theoretical analysis of these decays based on the QCD factorization framework, and constraining the CKM-Wolfenstein parameters from the unitarity fits, our results yield B-barth[B→(ρ,ω)γ]=(1.38±0.42)x10-6 and R-barth[(ρ,ω)γ/K*γ]=(3.3±1.0)%, in agreement with the BELLE data. Leaving instead the CKM-Wolfenstein parameters free, our analysis gives (at 68% C.L.) 0.16≤ vertical bar Vtd/Vts vertical bar ≤0.29, which is in agreement with but less precise than the indirect CKM-unitarity fit of the same, 0.18≤ vertical bar Vtd/Vts vertical bar ≤0.22. The isospin-violating ratio in the B→ργ decays and the SU(3)-violating ratio in the Bd0→(ρ0,ω)γ decays are presented together with estimates of the direct and mixing-induced CP-asymmetries in the B→(ρ,ω)γ decays within the SM. Their measurements will overconstrain the angle α of the CKM-unitarity triangle