  The typical scalar field theory has a cosmological constant problem. We
propose a generic mechanism by which this problem is avoided at tree level by
embedding the theory into a larger theory. The metric and the scalar field
coupling constants in the original theory do not need to be fine-tuned, while
the extra scalar field parameters and the metric associated with the extended
theory are fine-tuned dynamically. Hence, no fine-tuning of parameters in the
full Lagrangian is needed for the vacuum energy in the new physical system to
vanish at tree level. The cosmological constant problem can be solved if the
method can be extended to quantum loops.
