Five–Branes and Supersymmetry Breaking in M–Theory

Supersymmetry breaking via gaugino condensation is studied in vacua of heterotic M–theory with five–branes. We show that supersymmetry is still broken by a global mechanism and that the non–perturbative superpotential takes the standard form. When expressed in terms of low energy fields, a modification arises due to a threshold correction in the gauge kinetic function that depends on five–brane moduli. We also determine the form of the low energy matter field Kähler potential. These results are used to discuss the soft supersymmetry breaking parameters, in particular the question of universality.