Long-time behavior of Granular Gases with impact-velocity dependent   coefficient of restitution
  A gas of particles which collide inelastically if their impact velocity exceeds a certain value is investigated. In difference to common granular gases, cluster formation occurs only as a transient phenomenon. We calculate the decay of temperature due to inelastic collisions. In spite of the drastically reduced dissipation at low temperature the temperature surprisingly converges to zero. 
Thorsten Poeschel, Nikolai V. Brilliantov, and Thomas Schwager