The CKM phase $\alpha$ through $B\to a_0\pi$

Abstract

We propose the decay modes $B\to a_0(\to \eta \pi )\pi$ to determine the CKM phase $\alpha$. One can analyze these modes through (i) the $B\to a_0\pi$ isospin pentagon, (ii) the time dependent Dalitz plot of $B^0(t)\to a_0^{\pm }{\pi }^{\mp }\to \eta {\pi }^{+}{\pi }^{-}$, and (iii) the time dependence of $B^0(t)\to a_0^0(\to \eta {\pi }^0){\pi }^0$. We show that the $a_0\pi$ modes have certain advantages as compared to the $\rho \pi$ modes, and strongly recommend the time dependent Dalitz plot analysis in the $a_0\pi$ channel.

Comments: 11 pages RevTeX, the final version to be published in Phys. Rev. D. A few changes made in the text and the table