|Vub| from exclusive semileptonic B→π decays

We use Omnes representations of the form factors f(+) and f(0) for exclusive semileptonic B -> pi decays, paying special attention to the treatment of the B* pole and its effect on f(+). We apply them to combine experimental partial branching fraction information with theoretical calculations of both form factors to extract vertical bar V-ub vertical bar. The precision we achieve is competitive with the inclusive determination and we do not find a significant discrepancy between our result. vertical bar V-ub vertical bar (3.90 +/- 0.32 +/- 0.18) x 10(-3), and the inclusive world average value, (4.45 +/- 0.20 +/- 0.26) x 10(-3) [Heavy Flavor Averaging Group (HFAG, hep-ex/0603003]. (C) 2007 Elsevier B.V. All rights reserved.