Testing the decoherence of a macroscopic object using a quantum optical probe

Summary form only given. We describe how a quantum optical system can be used to probe the rules according to which the decay of a superposition of spatially separated states of a macroscopic object takes place. We consider a system composed of an electromagnetic field mode inside a cavity exerting pressure on a movable harmonically oscillating mirror of the cavity. Both the movable mirror and the cavity field are treated as quantum harmonic oscillators with the number operator of the field being coupled to the position operator of the mirror.