The effect of Wilson line moduli on CP-violation by soft supersymmetry breaking terms

The CP-violating phases in the soft supersymmetry-breaking sector in orbifold compactifications with a continuous Wilson line are investigated. In this case the modular symmetry is the Siegel modular group Sp(4,Z) of genus two. In particular, we study the case that the hidden sector non-perturbative superpotential is determined by the Igusa cusp form C12 of modular weight 12. The effect of large non-perturbative corrections to the dilaton Kähler potential on the resulting CP-violating phases is also investigated.