Line of continuous phase transitions in a three dimensional U(1) model   with 1/r^2 current-current interactions
  We study a lattice model of interacting loops in three dimensions with a $1/r^2$ interaction. Using Monte Carlo, we find that the phase diagram contains a line of second-order phase transitions between a phase where the loops are gapped and a phase where they proliferate. The correlation length exponent and critical conductivity vary continuously along this line. Our model is exactly self-dual at a special point on the critical line, which allows us to calculate the critical conductivity exactly at this point. 
Scott D. Geraedts and Olexei I. Motrunich
cond-mat.stat-mech