  We hypothesize that the uncontrolled interactions among the various
components of quantum mechanical bound states and the background fields,
sometimes known as virtual particle exchange, affect the state of the quantum
system as do typical scattering interactions. Then with the assumption that the
interior environment of unstable particles is disordered, we derive in the
limit of continuous internal interactions an exactly exponential decay
probability at all times and Fermi's Golden Rule for the decay rates. Our
result offers a resolution to the long-standing problems with the standard
theoretical treatments, such as the lack of exponential time evolution for
Hilbert Space vectors and energy spectra unbounded from below.
