  Here we propose a pair of experiments to distinguish the recently proposed
"slicing theory" of quantum measurement, which gives a transient many worlds
picture, and decoherence. Since these two theories are essentially "opposites"
in their approach and both claim to arise from the many body Schr\"odinger
equation itself, there is no chance of them being equivalent representations of
the same reality. It will be explicitly shown that each theory gives very
different answers to the questions of back reaction and revival of phase
effects after measurement. We suggest that the kinds of isolated systems now
possible in optical traps is now sufficient to generate a selective distinction
between these two theories. In particular we show that the slicing theory gives
examples of interference from "revival of histories" in controlled examples but
no back reaction on the measurement devices whereas decoherence gives the
opposite.
