Finding controlled, analytical approaches to the deconfinement transition in QCD is an old problem. Here we present a weak coupling calculation of the deconfinement transition in a deformed version of QCD. We argue that this transition is continuously connected to the transition in pure gauge theory, which takes place in strong coupling.
More technical abstract: We study the phase diagram of SU(2) Yang-Mills theory with one adjoint Weyl fermion on R^3xS^1 as a function of the fermion mass m and the compactification scale beta. This theory reduces to thermal pure gauge theory as m->infinity and to circle-compactified
(twisted) susy gluodynamics in the limit m->0. In the m-L plane, there is a line of center symmetry changing phase transitions. In the limit
m->infinity, this transition takes place at beta_c=1/T_c, where T_c is
the critical temperature of the deconfinement transition in pure Yang-Mills theory. We show that near m=0, the critical scale beta_c can be computed using semi-classical methods and that the transition is of second order.
This suggests that the deconfining phase transition in pure Yang-Mills theory is continuously connected to a phase transition that can be studied in weak coupling. The center symmetry changing phase transition arises from the competition of fractionally charged instanton-monopoles and instanton molecules. The calculation can be extended to higher rank gauge groups and non-zero theta angle.