The CW mechanism in a semi-definite system
Author: Alexander Söderberg Rousu
Preprint number: UUITP-06/23
We study the ϕ6−ϕ4 model with O(N)-symmetry near three dimensions. This model has a sextic bulk-interaction and a quartic boundary-interaction. The bulk two-point correlator is found upto two-loops by solving the equation of motion and applying the boundary conditions. Finally we apply the Coleman-Weinberg mechanism to this model, which allows us to flow along the renormalization group to a first-ordered phase transition. At one-loop order only the boundary receives a non-trivial effective potential, giving the scalar on the boundary a vacuum expecation value. However, due to the boundary operator product expansion, the bulk one-point function is non-zero as well. This leads to a spontaneous symmetry breaking of the original O(N)-symmetry.