  An exact analytical solution of the decaying wave function of two identical
noninteracting particles, which are entangled by spatial symmetry, is used to
analyze the effect of the resonance spectra in the propagation of the decaying
probability density outside the interaction potential region. We find, using
exactly solvable problems, that a usual approximation that considers the two
resonance levels associated with the initial states, is affected substantially
in the case of sharp high energy resonances by disrupting the pure exponential
decaying regime exhibited by the two resonance level approximation, whereas for
broad high energy resonances, we find that the probability density profile is
well described by the two resonance approximation.
