  Some false vacua do not decay via bounces. This usually happens when a flat
direction of the tunneling action due to scale invariance is lifted to a
sloping valley by a scale breaking perturbation, pushing the bounce off to
infinity. We compare two types of alternative decay configurations that have
been proposed recently to describe decay in such cases: pseudo-bounces and new
instantons. Although both field configurations are quite similar, we find that
the pseudo-bounce action is lower than the new instanton one and describes more
faithfully the bottom of the action valley. In addition, pseudo-bounces cover a
range of field space wider than new instantons and, as a result, lead to an
action that can be lower than the one for new instantons by orders of
magnitude.
