A Resolution to the Supersymmetric CP Problem with Large Soft Phases via D-branes

Abstract

We examine the soft supersymmetry breaking parameters that result from various ways of embedding the Standard Model (SM) on D-branes within the Type I string picture, allowing the gaugino masses and $μ$ to have large CP- violating phases. One embedding naturally provides the relations among soft parameters to satisfy the electron and neutron electric dipole moment constraints even with large phases, while with other embeddings large phases are not allowed. The string models provide some motivation for large phases in the soft breaking parameters. The results generally suggest how low energy data might teach us about Planck scale physics.

Figures (2)

• Figure 1: Illustration of the overlap between the regions allowed by the electron and neutron EDM constraints. We choose $m_{3/2}=150\, \rm{GeV}$, $\theta=0.2$ and $\tan\beta=2$, and assume that the EW symmetry is broken radiatively. Allowed points are shown for a)$\Theta_1=0.85$, b)$\Theta_1=\sqrt{\frac{1}{2}}$, and c)$\Theta_1=0.55$. The black circles are the points allowed for the eEDM and grey blocks for the nEDM. In a), the overlap is essentially total so only the grey blocks show up; in b) and c) the overlap becomes less good. The sensitivity is encouraging, suggesting that the experimental data can determine the Goldstino angles.
• Figure 2: Range of the electron and neutron EDM values vs. $\varphi_1=\varphi_3$ predicted by Eqs. (\ref{['model3']}) and (\ref{['model4']}) for the parameters of Figure 1 a). All of the points are allowed by the experimental bounds on the EDM's (note the different scales for the eEDM and nEDM).