About scattering and bound states

[luisgml_2000]

Hi!

I'd like to ask you what do the texts mean by scattering, bound and antibound states. The context for these concepts is scattering theory.

Thanks!

[malawi_glenn]

A bound state has E < 0

And scattering, well scattering is when you have a incident particle (wave function \psi _{in}(x) ) which accected by a potential (scatterer V(x) ) which leads to another (unbound) particle state (a new wave function [itex] \psi _{out}(x) [/itex).

That is perhaps the most simple explanation I can give, I am sure you will understand more later. Here are some good introductory material I used when I started with Quantum scattering:

http://www3.tsl.uu.se/thep/courses/QM/scattering-overview.pdf (very good, with pictures and history)

http://farside.ph.utexas.edu/teaching/qmech/lectures/node130.html (sort of a textbook)

http://www.theorie.physik.uni-muenchen.de/~serge/scattering1.pdf (summary of formulas)

Its better to ask specific questions, if you want a good answer :-) This was a quite general question.

It is also quite hard to answer you since you dont say what your text is, which book do you use? Isn't these things defined somewhere?

[comote]

I claim ignorance about anti-bound states.
A good reference about bound states and scattering states is D Ruelle "A remark on bound states in Potential Scattering theory" Nouvo Cimento V61A p655-662. It is a bit heavy on the math though.

The basic idea they give is that a bound state is any state which is "confined" to a compact region in space for all time. In contrast a scattering state will leave any compact region of space given enough time.

This makes sense if you think about it. A Bound state is "BOUND" to some finite region for all time where as a scattering state is not.