On the $\Delta A_{CP}$ saga

TL;DR

This paper proposes a model attributing large SU(3) flavor violations in D meson decays to final state interactions, predicting significant CP asymmetries with specific decay mode differences.

Contribution

It introduces a model emphasizing final state interactions as the sole source of flavor violations and predicts distinctive CP asymmetry patterns in D meson decays.

Findings

Large strong phase differences align with experimental branching ratios.

Predicted CP asymmetry for charged pions exceeds that for charged kaons.

Opposite signs of asymmetries in different decay modes are forecasted.

Abstract

We discuss a model in which the large SU(3) flavor violations in singly Cabibbo suppressed decays of neutral D mesons are ascribed exclusively to the final state interactions. The agreement with the experimental data on the branching ratios is obtained with large strong phase differences which are also necessary for substantial direct CP violation. While the value of the CP violating asymmetries depends on the strength of the penguin contribution, we predict an asymmetry for the decays into charged pions more than twice larger than that for charged kaons and having opposite sign.