Formal Description
Making use of WKB approximation we can write the wave function of the scattered system in term of action S:
Inserting the wavefunction Ψ in the Schrödinger equation we obtain
We write S as a ħ power series
For the zero-th order:
If we consider straight trajectories then .
We obtain a differential equation with the boundary condition:
for V → 0, z → -∞.
Read more about this topic: Eikonal Approximation
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