We consider a class of evolution equations in Lindblad form, which model the
dynamics of dissipative quantum mechanical systems with mean-field interaction.
Particularly, this class includes the so-called Quantum Fokker-Planck-Poisson
model. The existence and uniqueness of global-in-time, mass preserving
solutions is proved, thus establishing the existence of a nonlinear
conservative quantum dynamical semigroup. The mathematical difficulties stem
from combining an unbounded Lindblad generator with the Hartree nonlinearity.Comment: 30 pages; Introduction changed, title changed, easier and shorter
proofs due to new energy norm. to appear in Comm. Math. Phy