Motion of a granular particle on a rough line

We discuss a new model of ideal granular gas consisting of a particle bouncing inelastically along a rough inclined plane. Assuming a velocity-dependent inelastic interaction between the surface and the falling object we study the dynamical phase diagram which consists of three different phases: an accelerated motion, a stopping phase and a phase where the velocity fluctuates about a constant value. We analyze the statistical properties of the steady velocity regime and find that the velocity distribution is characterized by power law tails with a nonuniversal exponent β which depends on the nature of the surface. An explanation for this phenomenon is presented and its relation with random multiplicative processes expounded.