Walking near a conformal fixed point: The 2-d O(3) model at θ≈π 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 approximate to 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 mass gap close to the conformal point.