The discussion focuses on the T-matrix in two-body scattering, emphasizing the concept of "leading order" in perturbation theory. The T-matrix can be expressed as a power series in the coupling strength g, where the leading order corresponds to the first non-zero term, g^1. Additionally, the connection between Feynman diagrams in figure 2.3 and equations 2.24-2.26 is highlighted, illustrating their correspondence to terms in the perturbation series.
PREREQUISITESThis discussion is beneficial for physicists, particularly those specializing in quantum mechanics and scattering theory, as well as students seeking to deepen their understanding of T-matrix formalism and perturbation methods.
The T-matrix, whose precise definition must be given somewhere else in the book, can be expanded into a power series in the coupling strength g. The zeroth- order term is trivial, as it corresponds to no scattering at all. The term containing the lowest non-vanishing power of g (g^1 in this example) is the leading order.Bin Jiang said:Summary:: How to understand T-matrix in two-body scattering? Especially how to understand "leading order" in the text.
How can we understand T-matrix in two-body scattering? Especially term "leading order" in the text. In addition, how to understand the connection between fig2.3 and equation 2.24-2.26?
Thanks.