Interacting classical and quantum particles
  We apply Hall and Reginatto's theory of interacting classical and quantum ensembles to harmonically coupled particles, with a view to understanding its experimental implications. This hybrid theory has no free parameters and makes distinctive predictions that should allow it to be experimentally distinguished from quantum mechanics. It also bears on the questions of quantum measurement and quantum gravity. 
Alvin J. K. Chua, Michael J. W. Hall, C. M. Savage
quant-ph gr-qc