  A new approach to the cosmological constant problem is proposed by modifying
Einstein's theory of general relativity, using instead a scalar-tensor theory
of gravitation. This theory of gravity crucially incorporates the concept of
quantum symmetry breaking. The role of the cosmological constant $\lambda$ as a
graviton mass in the weak-field limit is necessarily utilized. Because
$\lambda$ takes on two values as a broken symmetry, so does the graviton mass
-- one of which cannot be zero. Gravity now exhibits both long- and short-range
forces, by introducing hadron bags into strong interaction physics using a
nonlinear, self-interacting scalar $\sigma$-field coupled to the gravitational
Lagrangian.
