  A two-body quantum correlation is calculated for a particle reflecting from a
moving mirror. Correlated interference results when the incident and reflected
particle substates and their associated mirror substates overlap. Using the
Copenhagen interpretation of measurement, an asynchronous joint probability
density (PDF), which is a function both of the different positions and
different times at which the particle and mirror are measured, is derived
assuming that no interaction occurs between each measurement. Measurement of
the particle first, in the correlated interference region, results in a
splitting of the mirror substate into ones which have and have not reflected
the particle. An analog of the interference from the Doppler effect for only
measurements of the particle (a marginal PDF), in this two-body system, is
shown to be a consequence of the asynchronous measurement. The simplification
obtained for a microscopic particle reflecting from a mesoscopic or macroscopic
mirror is used to illustrate asynchronous correlation interferometry. In this
case, the small displacement between these mirror states can yield negligible
environmental decoherence times. In addition, interference of these mirror
states does not vanish in the limit of large mirror mass due to the small
momentum exchange in reflecting a microscopic particle.
