Measurements of CP-violating asymmetries in B0→a1±(1260)π decays

Abstract

We present measurements of CP-violating asymmetries in the decay B0→a1±(1260)π with a1±(1260) →ππ±π±. The data sample corresponds to 384×106 BB̄ pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We measure the CP-violating asymmetry ACPa1π=-0.07±0. 07±0.02, the mixing-induced CP violation parameter Sa1π=0.37±0. 21±0.07, the direct CP violation parameter Ca1π=-0.10±0. 15±0.09, and the parameters ΔCa1π=0.26±0.15±0.07 and ΔSa1π=-0.14±0.21±0.06. From these measured quantities we determine the angle αeff=78.6°±7.3°. © 2007 The American Physical Society.