EPR experiments without “collapse of the wavefunction”

We discuss how to describe “EPR experiments”, in particular those presently in preparation for Φ → K0 K0 or T(4S) → B0 B0, without making use of the awkward language of “the collapse of the wavefunction”. We propose that instead of the wavefunction, the amplitude for a process — detection included, be given the central role. The amplitude method simplifies the considerations substantially; particularly, the lorentz covariance of the description becomes manifest. Furthermore, our covariant approach permits a unified treatment of the phase factors for all particle mixing problems. We obtain the relativistic corrections to the phase factors. Relative to a non-relativistic treatment, with “collapses” presumed to take place in the overall center of mass, we find that for Φ → K0 K0 these are on the order of five percent and perhaps observable. Implications for the fundamentals of quantum mechanics are briefly discussed.