The universality class of the electroweak theory

Rummukainen K, Tsypin M, Kajantie K, Laine M, Shaposhnikov M. The universality class of the electroweak theory. Nuclear Physics B. 1998;532(1-2):283-314.We study the universality class and critical properties of the electroweak theory at finite temperature. Such critical behaviour is found near the endpoint m(H) = m(H,c) of the line of first-order electroweak phase transitions in a wide class of theories, including the Standard Model (SM) and a part of the parameter space of the Minimal Sypersymmetric Standard Model (MSSM). We find that the location of the endpoint corresponds to the Higgs mass m(H,c) = 72(2) GeV in the SM with sin(2) theta(w) = 0, and m(H,c) 88 GeV, there is no electroweak phase transition in the SM. We compute the corresponding critical indices and provide strong evidence that the phase transitions near the endpoint fall into the three-dimensional Ising universality class. (C) 1998 Elsevier Science B.V