  In this paper we discuss the nonergodic behavior for a class of long-standing
quasi-stationary states in a paradigmatic model of long-range interacting
systems, i.e. the HMF model. We show that ensemble averages and time averages
for velocities probability density functions (pdfs) do not coincide and in
particular the latter exhibit a tendency to converge towards a q-Gaussian
attractor instead of the usual Gaussian one predicted by the Central Limit
Theorem, when ergodicity applies.
