We report an improved measurement of the partial-rate CP asymmetry in B±→K0π± decays. The analysis is based on a data sample of 85×106 BB̄ pairs collected at the Y(4S) resonance with the Belle detector at the KEKB e +e- storage ring. We measure ACP(K 0π±) = 0.07-0.08+0.09 +0.03+0.01, where the first and second errors are statistical and systematic, respectively; the corresponding 90% confidence-level interval is -0.10 <ACP(K0π±) <0.22.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics