Loop-Induced CP Violation in the Gaugino and Higgsino Sectors of Supersymmetric Theories

TL;DR

This paper demonstrates that supersymmetric gaugino and higgsino sectors can exhibit observable CP violation through radiative effects from large CP-violating couplings, with implications for neutron EDM measurements.

Contribution

It introduces a mechanism for CP violation in supersymmetric sectors via loop effects from trilinear couplings, not captured by renormalization-group evolution.

Findings

Large CP-violating effects can arise from loop corrections.

Calculated two-loop neutron EDM contribution from gluino chromo-EDM.

CP violation effects are phenomenologically significant.

Abstract

We show that the gaugino and higgsino sectors of supersymmetric theories can naturally acquire observable CP violation through radiative effects which originate from large CP-violating trilinear couplings of the Higgs bosons to the third-generation scalar quarks. These CP-violating loop effects are not attainable by evolving the supersymmetric renormalization-group equations from a higher unification scale down to the electroweak one. We briefly discuss the phenomenological consequences of such a scenario, and as an example, calculate the two-loop contribution to the neutron electric dipole moment generated by the one-loop chromo-electric dipole moment of the gluino.