Direct CPviolation in B→Kπdecays at Belle

We report recent measurements of direct CP violation in the decays B 0 →K + π − , B + →K + π 0 , B + →K 0 π + , and B 0 →K 0 π 0 , using a data sample containing 535 or 449×10 6 BB pairs collected with the Belle detector at the KEKB asymmetric‐energy e + e − collider operating at the Υlpar;4S) resonance. The measured CP violating asymmetries are A CP (K + π − ) = −0.094±0.018±0.008, A CP (K + π 0 ) = +0.07±0.03±0.01, A CP (K 0 π + ) = +0.03±0.03±0.01, and A CP (K 0 π 0 ) = −0.05±0.14±0.05. We observe direct CP violation with a significance of 4.8σ in B 0 →K + π − . With our measurements, a large deviation between A CP (K + π − ) and A CP (K + π 0 ) is found to be A CP (K + π 0 )−A CP (K + π − ) = +0.164±0.037, which corresponds to a significance of 4.4σ.