Quantifying Limits on CP Violating Phases from EDMs in Supersymmetry

TL;DR

This paper analyzes how current and future experimental limits on electric dipole moments constrain CP-violating phases in the constrained minimal supersymmetric standard model, despite the high supersymmetry breaking scale.

Contribution

It provides updated bounds on CP-violating phases in the CMSSM considering recent Higgs mass measurements and LHC results, highlighting the significance of EDM experiments.

Findings

Current EDM limits constrain CP phases to small fractions of pi.

Higher supersymmetry breaking scales still allow non-negligible CP phases.

Future EDM improvements could further tighten these constraints.

Abstract

We revisit the calculation of the electron, neutron, and proton electric dipole moments (EDMs) in the constrained minimal supersymmetric standard model (CMSSM). The relatively large mass of the Higgs boson, $m_H \simeq 125$ GeV coupled with the (as yet) lack of discovery of any supersymmetric particle at the LHC, has pushed the supersymmetry breaking scale to several TeV or higher. Though one might expect this decoupling to have relaxed completely any bounds on the two CP violating phases in the CMSSM ($\theta_\mu$ and $\theta_A$), the impressive experimental improvements in the limits on the EDMs (particularly the electron EDM) still allow us to set constraints of order $(0.01 - 0.1)\pi$ on $\theta_A$ and $(0.001 - 0.1)\pi$ on $\theta_\mu$. We also discuss the impact of future improvements in the experimental limits on supersymmetric models.