How to get the scattering angle of the nuclear reaction?

Hello everyone,
I’d like to identify the particle type produced by nuclear reactions, using the scattering angle and energy. Now I can know the energy, but how can I attain the scattering angle? where can I find relevant information?
He Chih-Hsuan


please, have a look into $G4INSTALL/examples/extended/hadronic/Hadr01

This example demonstrates how to analyze final state.