Large hierarchies from approximate R symmetries
  We show that hierarchically small vacuum expectation values of the superpotential in supersymmetric theories can be a consequence of an approximate R symmetry. We briefly discuss the role of such small constants in moduli stabilization and understanding the huge hierarchy between the Planck and electroweak scales. 
Rolf Kappl, Hans Peter Nilles, Saul Ramos-Sanchez, Michael Ratz, Kai   Schmidt-Hoberg, Patrick K.S. Vaudrevange