# Direct CP asymmetry in $D\to \pi^-\pi^+$ and $D\to K^-K^+$ in QCD-based approach

## TL;DR

This paper presents the first QCD-based calculation of direct CP asymmetries in specific D meson decays, using light-cone sum rules to provide Standard Model estimates without model-dependent assumptions.

## Contribution

It introduces a novel QCD-based approach using light-cone sum rules to compute hadronic matrix elements for CP violation in D decays, avoiding model-inspired amplitude decompositions.

## Key findings

- First QCD-based calculation of CP asymmetries in D decays.
- Provides Standard Model estimates for asymmetries in pion and kaon modes.
- Comments on potential improvements for the computational method.

## Abstract

We present the first QCD-based calculation of hadronic matrix elements with penguin topology determining direct CP-violating asymmetries in $D^0\to \pi^-\pi^+$ and $D^0\to K^- K^+$ nonleptonic decays. The method is based on the QCD light-cone sum rules and does not rely on any model-inspired amplitude decomposition, instead leaning heavily on quark-hadron duality. We provide a Standard Model estimate of the direct CP-violating asymmetries in both pion and kaon modes and their difference and comment on further improvements of the presented computation.