Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0 → D + D

We present an updated measurement of time-dependent C P asymmetries and the C P -odd fraction in the decay B 0 → D * + D * − using 232 × 10 6 B ¯¯¯ B pairs collected by the BABAR detector at the SLAC PEP-II B factory. We determine the C P -odd fraction to be 0.125 ± 0.044 ( stat ) ± 0.007 ( syst ) . The time-dependent C P 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 − sin  2 β , respectively, in the absence of penguin amplitude contributions.