Effective Field Theory Lagrangians for Baryons with Two and Three Heavy   Quarks
  By analogy with pNRQCD, we construct Effective Field Theories suitable to describe the heavy-quark sector of baryons made of two and three heavy quarks. A long-standing discrepancy between the hyperfine splitting of doubly heavy baryons obtained in the HQET and potential models is solved. The one-loop matching of the 4-quark operators of dimension 6 is provided. 
Nora Brambilla, Thomas Roesch and Antonio Vairo