ar X iv : h ep - l at / 0 40 90 44 v 1 1 2 Se p 20 04 A finite temperature investigation of the Georgi - Glashow model in 3 D ∗

where Dμφ = ∂μφ + i[Aμ, φ] with φ = φ σ/2. The model has 3 dimensionful bare parametrs, g = [mass],m0 = [mass], μ = [mass], which can be rewritten in terms of 1 dimensionful parameter, g, and 2 dimensionless, y = m20/g , x = μ/2g. When the adjoint scalar field acquires a non-zero vacuum expectation value (vev), the Higgs mechanism takes place and SU(2) is dinamically broken to U(1); as a consequence two gauge bosons, W, acquire a mass. At tree level, one finds M W±/g 4 = −x/y and M γ = 0, while the Higgs boson has a mass M H/g 4 = 2y and a vev φφ = −yg/x. Magnetic monopoles solutions [1,2] are instantons in the 3D case. Monopoles influence both the charged and neutral sector of the theory: they provide at the same time a mechanism of con-