Vertical bar V(ub)vertical bar from exclusive semileptonic B -> rho decays

We use Omnes representations of the form factors V, A(1) and A(2) for exclusive semileptonic B -> rho decays, and apply them to combine experimental partial branching fraction information with theoretical calculations of the three form factors to extract vertical bar V-ub vertical bar. We find vertical bar V-ub vertical bar = (2.8 +/- 0.2(stat)+/- 0.5(sys)) x 10(-3). where we have conservatively assumed a 20% systematic error to account for the use of the quenched approximation in the lattice QCD calculations of the form factors. This value of vertical bar V-ub vertical bar is slightly lower than the values extracted from exclusive semileptonic B -> pi decays, (3.47 +/- 0.29 +/- 0.03) x 10(…