Explaining B to K pi anomaly with non-universal Z boson

We study the effect of non-universal $Z$ boson in the decay modes $B to K pi$. In the standard model these modes receive dominant contributions from $b to s$ QCD penguins. Therefore, in this limit one expects $S_{pi^0 K^0} approx sin 2 beta $, $A_{pi^0 K^0} approx 0$ and $A_{pi^0 K^-} approx A_{pi^+ K^-}$. The corrections due to the presence of small non-penguin contributions is found to yield $S_{pi^0 K^0} > sin 2 beta $ and $Delta A_{CP}(K pi) simeq 2.5 %$. However, the measured value of $S_{pi^0 K^0}$ is less than $ sin 2 beta $ and $Delta A_{CP}(K pi) simeq 15 %$. We show the model with a non-universal $Z$ boson can successfully explain these anomalies.