Two-loop corrections to the B → π form factor from QCD sum rules on the light-cone and |Vub|

We calculate the leading-twist O(alpha(2)(s)beta(0)) corrections to the B -> pi transition form factor f(+)(0) in light-cone sum rules. We find that, as expected. there is a cancellation between the O(alpha(2)(s)beta(0)) corrections to f(B)f(+)(0) and the large corresponding corrections to f(B), calculated in QCD sum rules. This suggests the insensitivity of the form factors calculated in the light-cone sum rules approach to this source of radiative corrections. We further obtain an improved determination of the CKM matrix element vertical bar V-ub vertical bar, using latest results from BaBar and Belle for f(+)(0)vertical bar V-ub vertical bar.