Measurement of Time-DependentCPAsymmetries and theCP-Odd Fraction in the DecayB0→D*+D*−

Abstract

We present an updated measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0→D*+D*− using 232×106BB¯ pairs collected by the BABAR detector at the SLAC PEP-II B factory. We determine the CP-odd fraction to be 0.125±0.044(stat)±0.007(syst). The time-dependent CP asymmetry parameters C+ and S+ are determined to be 0.06±0.17(stat)±0.03(syst) and −0.75±0.25(stat)±0.03(syst), respectively. The standard model predicts these parameters to be 0 and −sin2β, respectively, in the absence of penguin amplitude contributions.Received 30 June 2005DOI:https://doi.org/10.1103/PhysRevLett.95.151804©2005 American Physical Society