I am enough deep in QFT to know Goldstone model and Higgs phenomenon. I like to see an example from quantum mechanics with square well or something like it not field theory or classical mechanics . I've read some in Sakurai book but not sure I understood right. Seems I've understood math but not...
Does anybody have an enough simple example and explanation of spontaneous breaking symmetry in quantum mechanics? When does the process of breaking take place? After or before some small perturbation appears?
If somebody of you is interested in reading what contemporary physicist thinks about the problem try [PLAIN]www.quniverse.sk/buzek/zaujimave/p343_s.pdf[/URL] . As an attracting example let me give you a very small citation:
"But what of psi (r) itself? Why is it a complex number,
composed of...