Study of localized CP violation in B- → π- π+π- and the branching ratio of B- → σ(600)π- in the QCD factorization approach

In this work, within the QCD factorization approach, we study the localized integrated CPviolation in the B- -> pi(-) pi(+) pi(-) decay and the branching fraction of the B- -> sigma pi(-) decay. Both the resonance and nonresonance contributions are included when we study the localized CPasymmetry in the B- -> pi(-) pi(+) pi(-) decay. The resonance contributions from the scalar sigma(600) and vector rho(0)(770) mesons are included. For the sigma(600) meson, we apply both the Breit-Wigner and Bugg models to deal with its propagator, and obtain B(B- -> sigma(600)pi(-)) < 1.67 x 10(-6) and B(B- -> sigma(600)pi(-)) < 1.946 x10(-5) in these two models, respectively. We find that there is no allowed divergence parameters.Sand fSto satisfy the experimental data A(CP) (pi(-) pi(+) pi(-)) = 0.584 +/- 0.082 +/- 0.027 +/- 0.007 in the region m(pi+pi-high)(2) > 15GeV(2) and m(pi+pi-low)(2) < 0.4GeV(2) and the upper limit of B(B--> sigma(600)pi(-)) in the Breit-Wigner model, however, there exists the region rho(S) is an element of[1.70, 3.34] and phi(S) is an element of[0.50, 4.50] satisfying the data for A(CP)(pi(-) pi(+) pi(-)) and the upper limit of B(B- -> sigma(600)pi(-)) in the Bugg model. This reveals that the Bugg model is more plausible than the Breit-Wigner model to describe the propagator of the sigma(600) meson even though the finite width effects are considered in both models. The large values of rho(S) Sindicate that the contributions from weak annihilation and hard spectator scattering processes are both large, especially, the weak annihilation contribution should not be neglected for B decays to final states including a scalar meson. (C) 2019 The Author(s). Published by Elsevier B.V.