Heavy-quark expansion for D and B mesons in nuclear matter
  The planned experiments at FAIR enable the study of medium modifications of $D$ and $B$ mesons in (dense) nuclear matter. Evaluating QCD sum rules as a theoretical prerequisite for such investigations encounters heavy-light four-quark condensates. We utilize an extended heavy-quark expansion to cope with the condensation of heavy quarks. 
Thomas Buchheim, Thomas Hilger, Burkhard Kampfer
nucl-th hep-ph