Glass transition in granular media

In the framework of schematic hard-spheres lattice models for granular media we investigate the phenomenon of the "jamming transition". In particular, using Edwards' approach, by analytical calculations at a mean-field level, we derive the system phase diagram and show that "jamming" corresponds to a phase transition from a "fluid" to a "glassy" phase, observed when crystallization is avoided. Interestingly, the nature of such a "glassy" phase turns out to be the same found in mean-field models for glass formers.