Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France.
We search for the rare flavor-changing neutral-current decay B+ -> K+ v (v) over tilde in a data sample of 82 fb(-1) collected with the BABAR detector at the PEP-II B-factory. Signal events are selected by examining the properties of the system recoiling against either a reconstructed hadronic or semileptonic charged-B decay. Using these two independent samples we obtain a combined limit of B(B+ -> K+ v (v) over bar) < 5.2 x10(-5) at the 90% confidence level. In addition, by selecting for pions rather than kaons, we obtain a limit of B(B+ -> pi(+) v (v) over bar) < 1.0 x 10(-4) using only the hadronic B reconstruction method.