  Based on a re-formulation of the classical explanation of quantum mechanical
Gaussian dispersion (Groessing et al. 2010) as well as interference of two
Gaussians (Groessing et al. 2012), we present a new and more practical way of
their simulation. The quantum mechanical "decay of the wave packet" can be
described by anomalous sub-quantum diffusion with a specific diffusivity
varying in time due to a particle's changing thermal environment. In a
simulation of the double-slit experiment with different slit widths, the phase
with this new approach can be implemented as a local quantity. We describe the
conditions of the diffusivity and, by connecting to wave mechanics, we compute
the exact quantum mechanical intensity distributions, as well as the
corresponding trajectory distributions according to the velocity field of two
Gaussian wave packets emerging from a double-slit. We also calculate
probability density current distributions, including situations where phase
shifters affect a single slit's current, and provide computer simulations
thereof.
