Head-on collision between two solitary waves in a one-dimensional bead chain
Wang Fu-Gang1, Yang Yang-Yang1, Han Juan-Fang1, 2, Duan Wen-Shan1, 2, †
       

(color online) The definition of the phase lags of solitary waves. The arrows stand for the propagation directions of waves, the red solid line represents the solitary wave L without collision and the black solid line represents solitary wave L after collision. “Δ” stands for the phase shift.