  We have studied the evolution of an excited electron bubble in superfluid 4He
for several tens of picoseconds combining the dynamics of the liquid with an
adiabatic evolution for the electron. The path followed by the excited bubble
in its decay to the ground state is shown to strongly depend on pressure. While
for pressures below 1 bar the 1P excited electron bubble has allowance for
radiatively decay to the deformed ground state, evolving then non-radiatively
towards the ground state of the spherical electron bubble, we have found that
above 1 bar two distinct baby bubbles appear in the course of the dynamical
evolution, pointing to a different relaxation path in which the electron may be
localized in one of the baby bubbles while the other collapses, allowing for a
pure radiationless de-excitation. Our calculations are in agreement with
experiments indicating that relaxed 1P bubbles are only observed for pressures
smaller than a critical one, of the order of 1 bar, and that above this value
the decay of the excited bubble has to proceed differently. A similar analysis
carried out for the 2P bubble shows that the adiabatic approximation fails at
an early stage of its dynamical evolution due to the crossing of the 2P and 1F
states.
