  We study interacting Dirac quasiparticles in disordered graphene and find
that an interplay between the unscreened Coulomb interactions and
pseudo-relativistic quasiparticle kinematics can be best revealed in the
ballistic regime, whereas in the diffusive limit the behavior is qualitatively
(albeit, not quantitatively) similar to that of the ordinary 2DEG with
parabolic dispersion. We calculate the quasiparticle width and density of
states that can be probed by photoemission, tunneling, and magnetization
measurements.
