HOT TOPICS AT BELLE

摘要

The measurement of the partial rate asymmetries for various B → Kπ decay modes is presented. A significant asymmetry is measured for the decay mode B → K~+π~- with A_(CP) = -0.101 ± 0.025 ± 0.005 which has a significance of 3.9σ and thus indicates evidence for direct CP violation. Furthermore the first observation of the decay mode B → π~0π~0 with a branching fraction of B(B→ π~0π~0) = (2.3_(-0.5)~(+0.4) ± 0.2) x 10~(-6) having a significance of 6.0 σ is presented accompanied with the first measurement of the CP asymmetry in this mode.