Constraints on Explicit CP Violation from the Brookhaven Muon g-2 Experiment

Abstract

We use the recently derived CP phase dependent analytic results for the supersymmetric electro-weak correction to $g_μ-2$ to constrain the explicit CP phases in softly broken supersymmetry using the new physics effect seen in the g-2 Brookhaven measurement. It is shown that the BNL data strongly constrains the CP violating phase $θ_μ$ (the phase of the Higgs mixing parameter $μ$) and $ξ_2$ (the phase of the SU(2) gaugino mass $\tilde m_2$) and as much as 60-90% of the region in the $ξ_2-θ_μ$ plane is eliminated over a significant region of the MSSM parameter space by the BNL constraint. The region of CP phases not excluded by the BNL experiment allows for large phases and for a satisfaction of the EDM constraints via the cancellation mechanism. We find several models with large CP violation which satisfy the EDM constraint via the cancellation mechanism and produce an $a_μ^{SUSY}$ consistent with the new physics signal seen by the Brookhaven experiment. The sparticle spectrum of these models lies within reach of the planned accelerator experiments.