Measurements of time-dependent CP asymmetries in B0→D(*)+D(*)− decays

Abstract

We present new measurements of time-dependent C P asymmetries for B 0 → D ( * ) + D ( * ) − decays using ( 467 ± 5 ) × 10 6 B ¯¯¯ B pairs collected with the BABAR detector located at the PEP-II B Factory at the Stanford Linear Accelerator Center. We determine the C P -odd fraction of the B 0 → D * + D * − decays to be R ⊥ = 0.158 ± 0.028 ± 0.006 and find C P asymmetry parameters S + = − 0.76 ± 0.16 ± 0.04 and C + = + 0.00 ± 0.12 ± 0.02 for the C P -even component of this decay and S ⊥ = − 1.80 ± 0.70 ± 0.16 and C ⊥ = + 0.41 ± 0.49 ± 0.08 for the C P -odd component. We measure S = − 0.63 ± 0.36 ± 0.05 and C = − 0.07 ± 0.23 ± 0.03 for B 0 → D + D − , S = − 0.62 ± 0.21 ± 0.03 and C = + 0.08 ± 0.17 ± 0.04 for B 0 → D * + D − , and S = − 0.73 ± 0.23 ± 0.05 and C = + 0.00 ± 0.17 ± 0.03 for B 0 → D + D * − . For the B 0 → D * ± D ∓ decays, we also determine the C P -violating asymmetry A = + 0.008 ± 0.048 ± 0.013 . In each case, the first uncertainty is statistical and the second is systematic. The measured values for the asymmetries are all consistent with the standard model.