On Partial Compositeness and the CP Asymmetry in Charm Decays

Preprint number: CP3-Origins-2012-13 and DIAS-2012-14
Authors: Boaz Keren-Zur (EPFL, Lausanne), Paolo Lodone (EPFL, Lausanne), Marco Nardecchia (CP3-Origins & DIAS), Duccio Pappadopulo (EPFL, Lausanne), Riccardo Rattazzi (EPFL, Lausanne), and Luca Vecchi (LANL, Los Alamos)
External link: arXiv.org

Recently, the LHCb and CDF collaborations reported the measure of an unexpectedly large direct CP asymmetry in D meson decays. In this paper we ask if new physics associ- ated with Partial Compositeness could plausibly explain this result. We find that Composite Higgs models with mass scale around 10 TeV can account for it, while marginally satis- fying all other flavor constraints in the quark sector. The minimal framework is however inadequate in the lepton sector due to the strong constraint from μ → eγ. This tension can be efficiently alleviated by realizing Partial Compositeness within Supersymmetry. The resulting models can saturate the CP asymmetry in D decays for superpartner masses close to the TeV scale and somewhat large A-terms. The supersymmetric realization of Partial Compositeness also offers a predictive and phenomenologically viable organizing principle for R-Parity violation, and may result in very distinctive signatures at hadron colliders. With or without Supersymmetry, the neutron EDM is expected to be around the present experimental sensitivity.