title: Precision model independent determination of |Vub| from B --> pilnu.
abstract: A precision method for determining |V(ub)| using the full range in q(2) of B --> pilnu 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 --> pipi using the soft-collinear effective theory, and the shape is constrained using QCD dispersion relations. We find |V(ub)| = (3.54 +/- 0.170 +/- 0.44) x 10(-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.
authors.affiliation: Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, 02139, USA.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Arnesen
authors.forename: Benjamin
authors.initials: B
authors.lastname: Grinstein
authors.forename: Ira Z
authors.initials: IZ
authors.lastname: Rothstein
authors.forename: Iain W
authors.initials: IW
authors.lastname: Stewart