  We study the phase diagram for two-color QCD in three-dimensional spacetime,
as a function of temperature and baryon chemical potential, using the
low-energy effective Lagrangian approach. We show one-loop renormalizability at
zero temperature, and then use the one-loop effective Lagrangian at finite
temperature and chemical potential to show that at low temperature there is a
critical line separating the normal and diquark phase, with this critical line
ending at a tricritical point. This phase structure is qualitatively similar to
that found recently by Splittorff et al for two-color QCD in four-dimensional
spacetime, although the details are quite different, due to the different
symmetries and the different loop and infrared properties of three-dimensional
spacetime.
