Walking near a Conformal Fixed Point: the 2-d O(3) Model at theta near   pi as a Test Case
  Slowly walking technicolor models provide a mechanism for electroweak symmetry breaking whose nonperturbative lattice investigation is rather challenging. Here we demonstrate walking near a conformal fixed point considering the 2-d lattice O(3) model at vacuum angle $\theta \approx \pi$. The essential features of walking technicolor models are shared by this toy model and can be accurately investigated by numerical simulations. We show results for the running coupling and the beta-function and we perform a finite size scaling analysis of the massgap close to the conformal point. 
Philippe de Forcrand, Michele Pepe and Uwe-Jens Wiese
hep-lat cond-mat.stat-mech hep-ph hep-th