Question

I have small doubt:
In compound nucleus theory, why the decay mode is independent of the formation mode.

Answer 1

The simplest explanation is that if formed a compound nucleus has a sufficient lifetime to exist as a excited state of the coalition of the projectile and target. Dthis time is long compared to the transit time of the projectile. During this time the energy within the compound nucleus is distributed throughout the nucleus thus loosing any correlation with the initiating reaction. The compound nucleus with its own unique quantum number then decays to allowed final states.