Resonance catalyzed CP asymmetries in D -> P l+ l-

TL;DR

This paper explores how resonance effects can induce CP asymmetries in rare charm meson decays, providing a potential signal of new physics beyond the Standard Model through model-independent analysis.

Contribution

It introduces a novel approach to detect CP violation in rare D meson decays by analyzing resonance interference effects, highlighting observables sensitive to new physics.

Findings

CP asymmetries can reach up to 1% and 10% in specific decays.

Resonance effects significantly influence CP asymmetry observables.

Model-independent analysis identifies promising decay channels for new physics detection.

Abstract

Recently observed increase of direct CP asymmetry in charm meson nonleptonic decays is difficult to explain within the SM. If this effect is induced by new physics, this might be investigated in other charm processes. We propose to investigate new CP violating effects in rare decays $D \to P \ell^+ \ell^-$, which arise due to the interference of resonant part of the long distance contribution and the new physics affected short distance contribution. Performing a model independent analysis, we identify as appropriate observables the differential direct CP asymmetry and partial decay width CP asymmetry. We find that in the most promising decays $D^+ \to \pi^+ \ell^+ \ell^-$ and $D_s^+ \to K^+ \ell^+ \ell^-$ the "peak-symmetric" and "peak-antisymmetric" CP asymmetries are strong phase dependent and can be of the order 1% and 10%, respectively.