it is also important to note that due to experimental constraints and the nature of quantum mechanics different possible processes interfere with eachother. eg

it is also important to note that due to experimental constraints and the nature of quantum mechanics different possible processes interfere with eachother. eg: (a+b)^2 = a^2 + b^2 + 2ab That 2ab is an interference term so a different process can get mixed in (quantum mechanically speaking). And we may not experimentally be able to disentangle it.