High energy density spots and production of kink-antikink pairs in   particle collisions
  The maximal energy density that can be achieved in the collisions of the particle-like wave trains in the $\phi^4$ model has been investigated numerically for different wave train parameters. From these results the prediction is made on how many kink-antikink pairs can be produced in wave train collisions taking into account that in collision of $N$ kinks maximal energy density is equal to $N^2/2$ for even $N$. Our numerical results are in a reasonably good agreement with the predicted maximal number of kink-antikink pairs formed in wave train collisions. 
Alidad Askari, Danial Saadatmand, Sergey V. Dmitriev, Kurosh Javidan
nlin.PS