Question

Spontaneously broken linear sigma model in Peskin & Schroeder: where is the miracle?

Answer 1

Hey mate ^_^

You are spectacularly misreading the book. In particular, you don't seem to understand the contrapositive of the miracle, the actual point they are making in the last paragraph of p 353.....

The miracle is not renormalizable, which they assure, but the fact the corrections regiment themselves to preserve the symmetry which is still there, despite the apparent disappearance of the visible manifestations of the symmetry....

#Be Brainly❤️

Answer 2

Hey,
I am not sure that your answer does anything else than restating the problem. In fact if you look at the classical Lagrangian in terms of ππ and σσEq 11.9 in P&S and would give each interaction a separate coupling, then you can introduce 6 counterterms and 2 field strength renormalisation factors. There are also 8 superficially divergent diagrams. Hence, where is the miracle?