Use of Glauber P distributions to characterize entanglement

Engangled states are a rich part of quantum mechanics that may have use in various computational and communication schemes, but for mixed or multipartite systems there is no good measure of entanglement, or a cirteria to deterime if a state is entangled or not. Nonclassical states always have a Glauber P distribution that takes on a negative value. We explore joint distribution properties to try and find ways to characterize the amount or presence of entanglement.