Primitive ontology and quantum state in the GRW matter density theory
  The paper explains in what sense the GRW matter density theory (GRWm) is a primitive ontology theory of quantum mechanics and why, thus conceived, the standard objections against the GRW formalism do not apply to GRWm. We consider the different options for conceiving the quantum state in GRWm and argue that dispositionalism is the most attractive one. 
Matthias Egg and Michael Esfeld
quant-ph physics.hist-ph