  False vacuum decay in field theory may be formulated as a boundary value
problem in Euclidean space. In a previous work, we studied its solution in
single scalar field theories with quadratic gravity and used it to find
obstructions to vacuum decay. For simplicity, we focused on massless scalar
fields and false vacua with a flat geometry. In this paper, we generalize those
findings to massive scalar fields with the same gravitational interactions,
namely an Einstein-Hilbert term, a quadratic Ricci scalar, and a non-minimal
coupling. We find that the scalar field reaches its asymptotic value faster
than in the massless case, in principle allowing for a wider range of theories
that may accommodate vacuum decay. Nonetheless, this hardly affects the
viability of the bounce in the scenarios here considered. We also briefly
consider other physically interesting theories by including higher-order
kinetic terms and changing the number of spacetime dimensions.
