QUANTUM AGING IN MEAN-FIELD MODELS

We study the real-time dynamics of quantum models with long-range inte ractions coupled to a heat bath within the closed-time path-integral f ormalism. We show that quantum fluctuations depress the transition tem perature. In the subcritical region there are two asymptotic time regi mes with (i) stationary and (ii) slow aging dynamics. We extend the qu antum fluctuation-dissipation theorem to the nonequilibrium case in a consistent way with the notion of an effective temperature that drives the system in the aging regime. The classical results are recovered f or (h) over bar --> 0.