CP violation in B^{pm} rightarrow π^{pm}π⁺π⁻ in the region with low invariant mass of one π⁺π⁻ pair

Recently, the large CP asymmetries in $B^\pm\to\pi^\pm\pi^+\pi^-$ decays were found by the LHCb Collaboration to localize in the region $m_{\pi^+\pi^-}^2<0.4 \text{GeV}^2$. We find such large localized CP asymmetries may be due to the interference between a light scalar and $\rho^0(770)$ intermediate resonances. Consequently, we argue that the distribution of CP asymmetries in the Dalitz plots of three-body B decays could be very helpful for identifying the presence of the scalar resonance.