Scaling limit of virtual states of triatomic systems
  For a system with three identical atoms, the dependence of the $s-$wave virtual state energy on the weakly bound dimer and trimer binding energies is calculated in a form of a universal scaling function. The scaling function is obtained from a renormalizable three-body model with a pairwise Dirac-delta interaction. It was also discussed the threshold condition for the appearance of the trimer virtual state. 
M.T. Yamashita, T. Frederico, A. Delfino, Lauro Tomio