The CKM phase $α$ through $B \to a_0 π$

Abstract

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