Measurements of partial branching fractions for (B)over-bar -> X(u)l(nu)over-bar and determination of vertical bar V(ub)vertical bar

We present partial branching fractions for inclusive charmless semileptonic B decays (B) over bar -> X(u)l (nu) over bar, and the determination of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V(ub)vertical bar. The analysis is based on a sample of 383 x 10(6) gamma(4S) decays into B (B) over bar pairs collected with the BABAR detector at the SLAC PEP-II e(+)e(-) storage rings. We select events using the invariant mass M(X) of the hadronic system, the invariant mass squared, q(2), of the lepton and neutrino pair, the kinematic variable P(+), or one of their combinations. We then determine partial branching fractions in limited regions of phase space: Delta B = (1.18 +/- 0.09(stat) +/- 0.07(syst) +/- 0.01(theor)) x 10(-3) (M(X) < 1.55 GeV/c(2)), Delta B = (0.95 +/- 0.10(stat) +/- 0.08(syst) +/- 0.01(theor)) x 10(-3) (P(+) < 0.66 GeV/c), and Delta B = (0.81 +/- 0.08(stat) +/- 0.07(syst) +/- 0.02(theor)) x 10(-3) (M(X) < 1.7 GeV/c(2), q(2) > 8 GeV(2)/c(4)). Corresponding values of vertical bar V(ub)vertical bar are extracted using several theoretical calculations.