Dispersive $\pi\pi\rightarrow K\bar K$ amplitude and giant CP violation in B to three light-meson decays at LHCb

TL;DR

This paper integrates a recent dispersive analysis of the $\pi\pi ightarrow Kar K$ amplitude into LHCb's framework, improving the understanding of giant CP violation in B-meson decays by accurately modeling final state interactions.

Contribution

It introduces a model-independent dispersive approach to describe $\pi\pi ightarrow Kar K$ scattering within LHCb analyses, enhancing the accuracy of CP violation studies in B decays.

Findings

Dispersive analysis aligns well with scattering data.

Improved modeling of final state interactions.

Supports the role of hadronic rescattering in CP violation.

Abstract

The LHCb collaboration has recently reported the largest CP violation effect from a single amplitude, as well as other giant CP asymmetries in several $B$-meson decays into three charmless light mesons. It is also claimed that this is predominantly due to $\pi\pi\rightarrow K\bar K$ rescattering in the final state, particularly in the 1 to 1.5 GeV region. In these analyses the $\pi\pi\rightarrow K\bar K$ amplitude is by default estimated from the $\pi\pi$ elastic scattering amplitude and does not describe the existing $\pi\pi\rightarrow K\bar K$ scattering data. Here we show how the recent model-independent dispersive analysis of $\pi\pi\rightarrow K\bar K$ data can be easily implemented in the LHCb formalism. This leads to a more accurate description of the asymmetry, while being consistent with the measured scattering amplitude and confirming the prominent role of hadronic final state interactions, paving the way for more elaborated analyses.