Evidence for direct CP violation in B0 → K+ π- decays

The evidence for direct charged particles (CP) violation in the decay B0→K+ π- was investigated with 253 fb-1 of data collected with the Belle detector at the KEKB e + e- collider. 275 x 106 BB̄ pairs were used to observe a B→K±π∓ signal with 2140 ±53 events. Mixing induced CP violation in the B sector was established in b → cc̄s transitions. The result suggests large interference between tree and penguin diagrams and the existence of final state interactions.