Double charm hadrons revisited
  The dynamics of two heavy quarks inside the same hadron is probed against the double charm baryon results of SELEX. This can be seen as a part of the mechanism to bind tetraquarks with two heavy quarks and two light antiquarks. In the framework of potential models, it is possible to test the role of different effects: relativistic corrections, confinement, hyperfine forces, etc. It is conjectured that an additional interaction rescaled from the nucleon--nucleon system and acting between light quarks only, can help in bringing extra, possibly required, binding in tetraquarks. 
J.-M. Richard and Fl. Stancu