ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA
We make a further study of the CP-violating asymmetry for the decays B(d)0 --> D+D-, pi+pi-, and K+pi-, which have both tree-level and penguin amplitudes. We confirm that the final-state phase shifts can lead to significant direct CP violation for these decays, and find that the absorptive part in the penguin amplitude can also lead to direct CP-violating asymmetry for each decay, which is about 5% in the standard model. The numerical predictions of the CP-violating asymmetries are given against final-state phase shifts, and they are quite different from those by Tanimoto et al. [Phys. Rev. D 42 (1990) 252].