Determination of |Vub| from measurements of the inclusive charmless semileptonic partial rates of B mesons using full reconstruction tags

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element data collected by the Belle detector at the KEKB e+e-asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Υ(4S). The signal for b→u semileptonic decay is distinguished from the b→c background using the hadronic mass MX, the leptonic invariant mass squared q2 and the variable P+≡EX-|p→X|. The results are obtained for events with pℓ*≥1GeV/c, in three kinematic regions (1)MX