Precision model independent determination of |Vub| from B→πlν -: art. no. 071802

A precision method for determining \V-ub\ using the full range in q(2) of B ->pi l nu data is presented. At large q(2) the form factor is taken from unquenched lattice QCD, at q(2)=0 we impose a model independent constraint obtained from B ->pi pi using the soft-collinear effective theory, and the shape is constrained using QCD dispersion relations. We find \V-ub\=(3.54 +/- 0.17 +/- 0.44)x10(-3). With 5% experimental error and 12% theory error, this is competitive with inclusive methods. Theory error is dominated by the input points, with negligible uncertainty from the dispersion relations.