The Energy of Scattering Solitons in the Ward Model
  The energy density of a scattering soliton solution in Ward's integrable chiral model is shown to be instantaneously the same as the energy density of a static multi-lump solution of the $\CP^3$ sigma model. This explains the quantization of the total energy in the Ward model. 
T. Ioannidou and N. S. Manton