PQCD analysis of exclusive charmless B meson decay spectra

We apply the perturbative QCD formalism, including Sudakov effects, to exclusive charmless semi-leptonic B meson decays. Predictions for both the charged lepton and lepton pair invariant mass spectra of the B → πℓν and B → ϱℓν decays in the large recoil region are presented. After combining soft pionn results, we extract |Vub| ≤ 4.5 × 10−3 from curren data. With our predictions, future data will not only provide a more precise extraction of |Vub|, but also test perturbative QCD in B meson decays.