Global CP asymmetries in charmless three-body $B$ decays with final state interactions

We propose a theoretical framework to understand the observable charge-parity (CP) violation in charmless three-body $B^\pm$ decays. The decay amplitudes put together the $ππ\to KK $ re-scattering and the U-spin symmetry, treated within a CPT invariant framework. This approach applied to a two-channel model provides the magnitudes and signs of the ratios of the global CP asymmetries for $B^\pm \to K^\pm π^+ π^- \,$, $B^\pm \to K^\pm K^+ K^- \,$, $B^\pm \to π^\pm K^+ K^- \,$ and $B^\pm \to π^\pm π^+π^- \,$ decays, compatible with those obtained from the available experimental data. In addition, by considering the neutral channels we predict the ratios for the global CP asymmetries for these decays.