Effective potential in glassy systems: theory and simulations

We study the phase diagram of glassy systems in the presence of an attracti ve coupling among real replicas. We find competition among a localized and a delocalized phase, that are separated by a coexistence line as in ordinar y first-order phase transitions. The coexistence line terminates in a criti cal point. We present numerical simulations for binary glasses in which we show that this scenario is realized. (C) 1998 Elsevier Science B.V. All rig hts reserved.