Direct CP violation in charm and flavor mixing beyond the SM

TL;DR

This paper explores potential explanations for recent LHCb evidence of CP violation in D meson decays, focusing on models beyond the Standard Model that involve flavor violation linked to chiral symmetry breaking, with implications for other observables.

Contribution

It identifies specific beyond Standard Model scenarios, such as disoriented A-terms and split families in supersymmetry, that could explain the observed CP violation and predicts related experimental signals.

Findings

Enhanced chromomagnetic operators can account for CP violation.

Predicted signals include nuclear EDMs near current bounds.

Possible deviations in K, B physics, and top quark processes.

Abstract

We analyze possible interpretations of the recent LHCb evidence for CP violation in D meson decays in terms of physics beyond the Standard Model. On general grounds, models in which the primary source of flavor violation is linked to the breaking of chiral symmetry (left-right flavor mixing) are natural candidates to explain this effect, via enhanced chromomagnetic operators. In the case of supersymmetric models, we identify two motivated scenarios: disoriented A-terms and split families. These structures predict other non-standard signals, such as nuclear EDMs close to their present bounds and, possibly, tiny but visible deviations in K and B physics, or even sizable flavor-violating processes involving the top quark or the stops. Some of these connections, especially the one with nuclear EDMs, hold beyond supersymmetry, as illustrated with the help of prototype non-supersymmetric models.