Optical theorem says that total cross section proportion to elastic scattering amplitude in the forward direction.Then if the target is absolutely reflective ''mirror''(in the case of quantum mechanics:scattering potential=infinity(r<a) and de Broglie wave leng limits to 0),in this case the scattering amplitude in forward direction is zero,but the total cross section is nonzero (because of reflection).So I do not understand the optical theorem.(adsbygoogle = window.adsbygoogle || []).push({});

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# A question about optical theorem

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