CP Violation and Flavor SU(3) Breaking in D-meson Decays

TL;DR

This paper performs a systematic flavor SU(3) analysis of D-meson decays, explaining recent CP asymmetry measurements and predicting asymmetries in various decay channels, highlighting the role of symmetry breaking effects.

Contribution

It introduces a comprehensive SU(3) symmetry breaking framework to account for CP asymmetry differences in D-meson decays, including an enhancement mechanism similar to the Δ=1/2 rule.

Findings

SU(3) breaking explains LHCb CP asymmetry measurements

Predictions made for asymmetries in specific decay channels

Asymmetry in D+→π+π0 decay vanishes at leading order

Abstract

We carry out a systematic flavor SU(3) analysis of D-meson decays including the leading order symmetry breaking effects. We find that SU(3) breaking can easily account for the recent LHCb measurement of the difference in CP asymmetries in the decays of $D^0$ into $K^+K^-$ and $\pi^+\pi^-$ mesons, once an enhancement mechanism, similar to the $\Delta=1/2$ rule in neutral kaon decays is assumed. As a byproduct of the analysis, one can make predictions regarding the individual asymmetries in $K^+K^-$, $\pi^+\pi^-$, as well as the $D^0 \to \pi^0\pi^0$ decay channels. Moreover, we find that the asymmetry in the decay $D^+\to \pi^+\pi^0$ vanishes in the leading approximation.