Measurement of CP-Violating Asymmetries in B0 to (rho pi)0 Using a Time-Dependent Dalitz Plot Analysis

We report a measurement of CP-violating asymmetries in B0 → (ρπ)0 → π+π-π0 decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 347 million Υ(4S) → B(bar B) decays, collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure 26 coefficients of the bilinear form factor terms occurring in the time-dependent decay rate of the B0 meson and derive the physically relevant quantities from these coefficients. In particular we find a three standard deviation evidence of direct CP-violation in the B0 → ρ±π#-+# decays, with systematic uncertainties included. We also achieve a constraint of the angle α of the Unitarity Triangle. All results presented are preliminary