# Relation between scattering amplitude and isospin

1. May 8, 2008

### Barny

Hi,

I'm an undergrad physicist in a bit of a pickle over how isospin relates to scattering amplitude.

It's been quoted to me that the scattering amplitude is given by the matrix element of the initial and final isospin states. I'd ideally like to show you this in latex, however I cant seem to work the latex thing that well so at a rough stab it would be <Ii,Ii3!H!If,If3>

here the lower case i and f represent initial and final states and H is the appropriate operator for this matrix element. I is total isospin andI3 represents the 3rd component of isospin.

Can anyone shed some light on this or point me to an appropriate text. The course text and documents are unsatisfactory as is Hughes and Giffiths (although in general i like these books alot)