Collision of two solitons for $1d$ Nonlinear Schrodinger Equation with same mass

We study the global dynamics of the collision of two solitons having the same mass for one-dimensional Nonlinear Schr\"odinger models with multi-power nonlinearity. For any natural number k, it is verified that if the incoming speed v between the two solitary waves is small enough, then, after the collision, the two solitons will move away with an outcoming speed vf=v+O(vᵏ) and the remainder of the solution will also have energy and weighted norms of order O(vᵏ). This is applied to several one-dimensional models such as the cubic NLS and the cubic-quintic NLS.