Explaining B→Kπ anomaly with nonuniversal Z′ boson

Abstract

We study the effect of a nonuniversal Z′ boson in the decay modes B→Kπ. In the standard model these modes receive dominant contributions from b→s QCD penguins. Therefore, in this limit one expects Sπ0K0 ≈sin 2β, Aπ 0K0≈0, and Aπ0K-≈Aπ+K-. The corrections due to the presence of small nonpenguin contributions is found to yield Sπ0K0 > sin 2β and ΔACP(Kπ) 2.5%. However, the measured value of Sπ0K0 is less than sin 2β and ΔACP(Kπ) 15%. We show the model with a nonuniversal Z′ boson can successfully explain these anomalies. © 2009 The American Physical Society.