Breaking CP and supersymmetry with orbifold moduli dynamics

Abstract

We consider the stabilization of string moduli and resulting soft supersymmetry-breaking terms in heterotic string orbifolds. Among the results obtained are: formulae for the scalar interaction soft terms without integrating out the hidden sector gaugino condensate, which reduce to standard expressions in the usual "truncated" limit; an expression for the modular transformation of A-terms; a study of the minima of the scalar potential in the Kaehler modulus direction; and a discussion of the implications for CP violation phenomenology. Some closely related results have appeared in a recent paper of Khalil, Lebedev and Morris, namely the exact modular invariance of A-terms up to unitary mixing, and the existence of certain complex minima for the moduli.