ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2002, vol. 89, p. 071801/1-071801/6
Study of CP-violating asymmetries in B0 → π+π- decays
The CP violation parameters in B0→π+π- decay were measured. The result for Sππ indicated that mixing-induced CP violation is large. The large Aππ term is an indication of direct CP violation in B meson decay, and suggests that there is a large hadronic phase and interference between the tree and penguin amplitudes. In this case the precise determination of sin2φ2 from Sππ requires additional measurements including the branching fractions for the decays B0→π0π0.