title: Noise activated granular dynamics.
abstract: We study the behavior of two particles moving in a bistable potential, colliding inelastically with each other and driven by a stochastic heat bath. The system has the tendency to clusterize, placing the particles in the same well at low drivings, and to fill all of the available space at high temperatures. We show that the hopping over the potential barrier occurs following the Arrhenius rate, where the heat bath temperature is replaced by the granular temperature. Moreover, within the clusterized "phase" one encounters two different scenarios: For moderate inelasticity, the jumps from one well to the other involve one particle at a time, whereas for strong inelasticity the two particles hop simultaneously.
authors.affiliation: Dipartimento di Fisica, Università La Sapienza and INFM Center for Statistical Mechanics and Complexity, Piazzale A. Moro 2, 00185 Rome, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Cecconi
authors.forename: Andrea
authors.initials: A
authors.lastname: Puglisi
authors.forename: Umberto Marini Bettolo
authors.initials: UM
authors.lastname: Marconi
authors.forename: Angelo
authors.initials: A
authors.lastname: Vulpiani