Nonperturbative flat direction decay

Abstract

We argue that supersymmetric flat direction vacuum expectation values can decay nonperturbatively via preheating. Considering a toy U(1) gauge theory, we explicitly calculate the scalar potential, in the unitary gauge, for excitations around several flat directions. We show that the mass matrix for the excitations has nondiagonal entries which vary with the phase of the flat direction vacuum expectation value. Furthermore, this mass matrix has zero eigenvalues whose eigenstates change with time. We show that these light degrees of freedom are produced copiously in the nonperturbative decay of the flat direction vacuum expectation value.