CP Violation in Multibody $B$ Decays from QCD Factorization

TL;DR

This paper evaluates a QCD factorization-based data-driven model for three-body B decays, comparing its predictions of CP violation with experimental data, highlighting its strengths and limitations, and discussing future improvements.

Contribution

It introduces a model for charmless three-body B decays based on QCD factorization and assesses its ability to reproduce CP violation measurements.

Findings

Model captures overall features of Dalitz plots

Cannot fully explain local CP asymmetries

Discussion on reducing model dependence

Abstract

We test a data-driven approach based on QCD factorization for charmless three-body $B$-decays by confronting it to measurements of CP violation in $B^- \to \pi^- \pi^+ \pi^-$. While some of the needed non-perturbative objects can be directly extracted from data, some others can, so far, only be modelled. Although this approach is currently model dependent, we comment on the perspectives to reduce this model dependence. While our model naturally accommodates the gross features of the Dalitz distribution, it cannot quantitatively explain the details seen in the current experimental data on local CP asymmetries. We comment on possible refinements of our simple model and conclude by briefly discussing a possible extension of the model to large invariant masses, where large local CP asymmetries have been measured.