Study of CP Asymmetries in Charmless Hadronic B Decays: Toward a Measurement of alpha

We present preliminary measurements of time-dependent CP asymmetries in neutral B meson decays to π+π- and π+π-π0 final states, where the latter is measured in the region of the Dalitz plane dominated by the ρ resonance. We also present preliminary measurements of the branching fraction for the decay B+ → π+π0 and an improved upper limit for B0 → π0π0, both of which are needed to extract the CP parameter α from the time-dependent CP asymmetry in the π+π- channel. These results are obtained from a data sample of approximately 88 million Υ(4S) → B(bar B) decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC