CKM $\gamma$ phase from $B \to K \pi \pi$

Abstract

We discuss a method to extract the CKM $\gamma$ angle combining Dalitz plot analysis of $B^{\pm} \to K^{\pm} \pi^+ \pi^-$ and untagged $B^0$, $\bar B^0 \to K_s \pi^+ \pi^-$. The method also allows obtaining the ratio and phase difference between the {\it tree} and {\it penguin} contributions from $B^0$ and $\bar B^0 \to K^{*\pm} \pi^{\mp} $ decays and direct CP asymmetry between $B^0$ and $\bar{B^0}$. From Monte Carlo studies of 100K events for the neutral mesons, we show the possibility of measuring $\gamma$ with a precision of $\sim 5^o$.