Electric dipole moments from Yukawa phases in supersymmetric theories

We study quark and electron EDMs generated by Yukawa couplings in supersymmetric models with different gauge groups, using the EDM properties under flavour transformations. In the MSSM (or if soft terms are mediated below the unification scale) the one-loop contributions to the neutron EDM are smaller than in previous computations based on numerical methods, although increasing as tan ³ β. A neutron EDM close to the experimental limits can be generated in SU(5), if tan β is large, through the u-quark EDM d_u, proportional to tan ⁴ β. This effect has to be taken into account also in SO(10) with large tan β, where d_u is comparable to the d quark EDM, proportional to tan β.