We report measurements of branching fractions and time-dependent CP asymmetries in B-0 -> D+D- and B-0 -> DD-+/-(-/+) decays using a data sample that contains (772 +/- 11) x 10(6)B (B) over bar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We determine the branching fractions to be B(B-0 -> D+D-) = (2.12 +/- 0.16 +/- 0.18) X 10(-4) and B(B-0 -> DD-+/-(-/+)) = (6.14 +/- 0.29 +/- 0.50) x 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 B-0 -> D+D- and A(DD) = +0.06 +/- 0.05 +/- 0.02, S-DD = -0.78 +/- 0.15 +/- 0.05, C-DD = -0.01 +/- 0.11 +/- 0.04, +/- Delta S-DD = -0.13 +/- 0.15 +/- 0.04 and Delta C-DD = +0.12 +/- 0.11 +/- 0.03 in B-0 -> DD-+/-(-/+), 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 4 sigma significance.
Matthias Finger, Konstantin Androsov, Qian Wang, Jan Steggemann, Yiming Li, Anna Mascellani, Varun Sharma, Xin Chen, Rakesh Chawla, Matteo Galli
Romain Christophe Rémy Fleury, Haoye Qin, Qiaolu Chen, Zhechen Zhang