Measurements of branching fractions and time-dependentCPviolating asymmetries inB0→D(*)±D∓decays

Abstract

We report measurements of branching fractions and time-dependent CP asymmetries in B0→D+D− and B0→D*±D∓ decays using a data sample that contains (772±11)×106BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We determine the branching fractions to be B(B0→D+D−)=(2.12±0.16±0.18)×10−4 and B(B0→D*±D∓)=(6.14±0.29±0.50)×10−4. We measure CP asymmetry parameters SD+D−=−1.06−0.14+0.21±0.08 and CD+D−=−0.43±0.16±0.05 in B0→D+D− and AD*D=+0.06±0.05±0.02, SD*D=−0.78±0.15±0.05, CD*D=−0.01±0.11±0.04, ΔSD*D=−0.13±0.15±0.04 and ΔCD*D=+0.12±0.11±0.03 in B0→D*±D∓, where the first uncertainty is statistical and the second is systematic. We exclude the conservation of CP symmetry in both decays at equal to or greater than 4σ significance.Received 29 March 2012DOI:https://doi.org/10.1103/PhysRevD.85.091106© 2012 American Physical Society