Changes

U | J m \rangle

U | J m \rangle

</math>

</math>

Instead of specifying the final-state particles' spin state via their helicities, we can first couple their spins together independent of their momentum direction, to obtain total spin ''S'', then couple ''S'' to their relative orbital angular momentum ''L'' to obtain their total angular momentum ''J''.   

 

This is one way to describe the final state, but it is not the only way.  Instead of specifying the final-state particles' spin state via their helicities, we can first couple their spins together independent of their momentum direction, to obtain total spin ''S'', then couple ''S'' to their relative orbital angular momentum ''L'' to obtain their total angular momentum ''J''.   

:<math>

:<math>

\langle \Omega \lambda_1 \lambda_2 | U | J m \rangle

\langle \Omega \lambda_1 \lambda_2 | U | J m \rangle