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 → π0 π0, 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) → BB̄ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics