  Based on the Bell theorem, it has been believed that a theoretical
computation of the Bell correlation requires explicit use of an entangled
state. Such a physical superposition of light waves occurs in the downconverter
sources used in Bell experiments. However, this physical superposition is
eliminated by wave propagation to spatially separated detectors. Bell
correlations must therefore result from local waves, and the source boundary
conditions of their previously entangled state. In the present model, Bell
correlations are computed from disentangled separated waves, boundary
conditions of nonlinear optics, and properties of single photon and vacuum
states specified by quantum electrodynamics. Transient interference is assumed
between photon excited waves and photon empty waves based on the possibility of
such interference found to be necessary by the designers of Bell experiment
sources. The present model employs local random variables without specifying
underlying causality
