The decay B-0 -> DK*(0) and the charge conjugate mode are studied using 1.0 fb(-1) of pp collision data collected by the LHCb experiment at /s = 7 TeV in 2011. The CP asymmetry between the B-0 -> DK*(0) and the B-0 -> DK*(0) decay rates, with the neutral D meson in the CP-even final state K+K- , is found to be A(d)(KK) = -0.45 +/- 0.23 +/- 0.02, where the first uncertainty is statistical and the second is systematic. In addition, favoured B-0 -> DK*(0) decays are reconstructed with the D meson in the non-CP eigenstate K+pi(-) . ratio of the B-flavour averaged decay rates in D decays to CP and non-CP eigenstates is measured to be R-d(KK) = 1.36 +/- 0.37 0.32 +/- 0.07, where the ratio of the branching fractions of D-0 -> K- pi(+) to D-0 -> K+K- decays is included as multiplicative factor. The CP asymmetries measured with two control channels, the favoured B-0 -> DK*(0) decay with D -> K-vertical bar pi(-) and the B-s(0) -> DK*(0) decay with D -> K+K-, are also reported.
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso