  We study energy relaxation in a phenomenological model for polymer built from
rheological considerations: a one dimensional nonlinear lattice with
dissipative couplings. These couplings are well known in polymer's community to
be possibly responsible of beta-relaxation (as in Burger's model). After
thermalisation of this system, the extremities of the chain are put in contact
with a zero-temperature reservoir, showing the existence of surprising
quasi-stationary states with non zero energy when the dissipative coupling is
high. This strange behavior, due to long-lived nonlinear localized modes,
induces stretched exponential laws. Furthermore, we observe a strong dependence
on the waiting time tw after the quench of the two-time intermediate
correlation function C(tw+t,tw). This function can be scaled onto a master
curve, similar to the case of spin or Lennard-Jones glasses.

Statistical Mechanics;Pattern Formation and Solitons