  We investigate energy dissipation and the distribution of particle velocities
at the jamming transition for overdamped shear-driven frictionless disks in two
dimensions at zero temperature. We find that the dissipation is caused by the
fastest particles and that the fraction of particles responsible for the
dissipation decreases towards zero as jamming is approached. These particles
belong to an algebraic tail of the velocity distribution that approaches $\sim
v^{-3}$ as jamming is approached. We further find that different measures of
the velocity diverge differently, which means that concepts like "typical
velocity" may no longer be used---a finding that should have implications for
analytical approaches to shear-driven jamming.
