Non-Relativistic Bose-Einstein Condensates, Kaon droplets, and Q- Balls
  We note the similarity between BEC (Bose-Einstein Condensates) formed of atoms between which we have long-range attraction (and shorter-range repulsions) and the field theoretic "Q balls". This allows us in particular to address the stability of various putative particle physics Q balls made of non-relativistic bosons using variational methods of many-body physics. 
Zohar Nussinov and Shmuel Nussinov