Measurement of branching fractions and CP-violating charge asymmetries for B-meson decays to D(*)D̄(*), and implications for the Cabibbo-Kobayashi-Maskawa angle γ

We present measurements of the branching fractions and charge asymmetries of B decays to all D(*)D̄(*) modes. Using 232×106 BB̄ pairs recorded on the Υ(4S) resonance by the BABAR detector at the e+e- asymmetric B factory PEP-II at the Stanford Linear Accelerator Center, we measure the branching fractions B(B0→D*+D*-)=(8.1±0. 6±1.0)×10-4, B(B0→D*±D)=(5.7±0.7±0. 7)×10-4, B(B0→D+D-)=(2.8±0.4±0.5)×10-4, B(B+→D*+D̄*0)=(8.1±1.2±1.2)×10-4, B(B+→D*+D̄0)=(3.6±0.5±0.4)×10-4, B(B+→D+D̄*0)=(6.3±1.4±1.0)×10-4, and B(B+→D+D̄0)=(3.8±0.6±0.5)×10-4, where in each case the first uncertainty is statistical and the second systematic. We also determine the limits B(B0→D*0D̄*0)<0.9×10-4, B(B0→D*0D̄0)<2.9×10-4, and B(B0→D0D̄0)<0. 6×10-4, each at 90% confidence level. All decays above denote either member of a charge-conjugate pair. We also determine the CP-violating charge asymmetries A(B0→D*±D)=0.03±0.10±0.02, A(B+→D*+D̄*0)=-0.15±0.11±0.02, A(B+→D*+D̄0)=-0.06±0.13±0.02, A(B+→D+D̄ *0)=0.13±0.18±0.04, and A(B+→D+D̄0)=-0. 13±0.14±0.02. Additionally, when we combine these results with information from time-dependent CP asymmetries in B0→D(*)+D(*)- decays and world-averaged branching fractions of B decays to Ds(*)D̄(*) modes, we find the Cabibbo-Kobayashi-Maskawa phase γ is favored to lie in the range (0.07-2.77) radians (with a +0 or +π radians ambiguity) at 68% confidence level. © 2006 The American Physical Society.