  A method of measuring relative probabilities of various gauge-field
configurations in the Yang-Mills vacuum was proposed long ago [Phys. Lett. B
223 (1989) 207]. We applied this method to compute the square of the YM vacuum
wave functional (VWF) in numerical simulations of SU(2) lattice gauge theory in
D=3+1 dimensions for sets of abelian plane waves. The results were compared to
predictions based on some VWF proposals in the literature. None of them
describes the data satisfactorily at large plane-wave momenta. The
phenomenological best fit to data, containing three free parameters, appears to
reduce in the continuum limit to the approximate form proposed in [Phys. Rev. D
77 (2008) 065003].
