  We study the long time dynamics of a quantum version of the
Sherrington-Kirkpatrick model. Time reparametrizations of the dynamical
equations have a parallel with renormalization group transformations, and
within this language the long time behaviour of this model is controlled by a
reparametrization group (R$_p$G) fixed point of the classical dynamics. The
irrelevance of the quantum terms in the dynamical equations in the aging regime
explains the classical nature of the violation of the fluctuation-dissipation
theorem.
