Atomic states are eigenstates of the atomic Hamiltonian. They are stationary states. Transitions from one atomic state to another are possible only in presence of an external perturbation e.g., the electromagnetic field.

Does the occurrence of radioactive beta decay have a similar explanation? More precisely, can we say that the states of the nucleus are eigenstates of the strong interaction Hamiltonian and beta decay happens due to weak interaction acting as the perturbation? If this is so, can someone give a reference?