Exclusive semileptonic b → uℓν decays at CLEO

Updated CLEO results are presented for branching ratios and four-momentum transfer, q², dependence of exclusive charmless semileptonic B decays, where the final state hadron is either a π, ρ, ω, η or η′. These results have comparable accuracies with those of other experiments. We address the issue of flavor singlet couplings by limiting Γ(B⁺ → η′ℓ⁺ν)/Γ(B ⁺ → ηℓ+ν) > 2.5 at 90% CL. We also extract a value of |V_ub| = (4.3 ± 0.4 ± 0.2_-0.4 ^+0.6) ×10^-3 in one particular unquenched lattice QCD model using πℓ⁺ν data above q² of 16 GeV ².