Study of Direct CP Violation in B(±)→J/ψK(±)(π(±)) Decays

Abstract

We present a search for direct CP violation in B(±)→J/ψK(±)(π(±)) decays. The event sample is selected from 2.8 fb(−1) of pp-bar collisions recorded by D0 experiment in run II of the Fermilab Tevatron Collider. The charge asymmetry ACP(B(+)→J/ψK(+))=+0.0075±0.0061(stat)±0.0030(syst) is obtained using a sample of approximately 40 000 B(±)→J/ψK(±) decays. The achieved precision is of the same level as the expected deviation predicted by some extensions of the standard model. We also measured the charge asymmetry ACP(B(+)→J/ψπ(+))=−0.09±0.08(stat)±0.03(syst).