  In this note we discuss the wave functional approach to the spectrum of pure
Yang-Mills theory in 2+1 and 3+1 dimensions by highlighting the issues of
dynamical mass generation and the role played by the kinetic term. We
extrapolate our recent analysis of 2+1 Yang-Mills theory to 3+1 dimensions, and
under certain heuristic assumptions use a simple quasi-Gaussian vacuum
wavefunctional for 3+1 Yang-Mills theory for a preliminary study of the
spectrum of glueballs which nicely fits the available lattice simulations.
