Branching fraction, polarization and CP-violating asymmetries in B0→D*+D*− decays

We present measurements of the branching fraction, the polarization parameters and CP-violating asymmetries in B0→D∗+D∗− decays using a 140 fb−1 data sample collected at the ϒ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e− collider. We obtain B(B0→D∗+D∗−)=[0.81±0.08(stat)±0.11(syst)]×10−3, R⊥=0.19±0.08(stat)±0.01(syst), R0=0.57±0.08(stat)±0.02(syst), S=−0.75±0.56(stat)±0.12(syst) and A=−0.26±0.26(stat)±0.06(syst). Consistency with Standard Model expectations is also discussed.