$\phi^6$ kink scattering
  In this paper, we investigate the scattering of two $\phi^6$ kinks and derive the real dynamics by solving the appropriate field equation numerically employing a Runga-Kutta method. We also use a collective coordinate approximation to find approximate dynamics, with the objective being to compare the approximate motion to the real dynamics in order to test the validity of this kind of approximation, which is used extensively in the study of solitons. 
Stephen W. Goatham
hep-th