Se p 20 09 Measurements of charmless B decays related to α at

We report recent measurements of the CKM angle α using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e− collider at the SLAC National Accelerator Laboratory. In addition to improved constraints on α from the decays B± → ρ±ρ0, we also present preliminary results of neutral and charged B meson decays to K1(1270)π and K1(1400)π and its impact on the estimate for the CKM angle α based on time-dependent analysis of CP-violating asymmetries in B0 → a1(1260)π. Moreover we report the first observation of the decay B → a1(1260)a1(1260); this mode can be used, in principle, to provide an indipendent measurement of α .