Measurement of CP-violating asymmetries in B^{0}→(ρπ)^{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 375×106 Υ(4S)→BB̅ 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. We derive the physically relevant quantities from these coefficients. In particular, we measure a constraint on the angle α of the unitarity triangle.