/sci/ - Science & Math

I can't understand how to interpret this graph, which should represent the cross section in the scattering of alpha particles on gold (the Rutherford experiment). The blue curve represents the calculated cross section for the nuclear Rutherford model, while the black one represents the uniform sphere Thompson model. What I don't understand is why the black one isn't a function: I expect the values to drop to 0 after 10^-3 radians because in the Thompson model the particles can't be scattered at large angles, but instead it turns back in a way that doesn't make any sense to me. Am I a brainlet or is the graph wrong? Anyone has an explanation? Thanks a lot.