Electroweak phase transition in Georgi-Machacek model

The Georgi-Machacek model extends the standard model Higgs sector by adding two isospin triplet scalar fields and imposing global SU(2)(R) symmetry on them. A feature of the model is that the triplets can acquire a large vacuum expectation value without conflicting with the current experimental bound on the rho parameter. We investigate the electroweak phase transition in the Georgi-Machacek model by evaluating the finite-temperature effective potential of the Higgs sector. The electroweak phase transition can be sufficiently strong in a large parameter space when the triplets acquire a vacuum expectation value of O(10) GeV, opening a possibility to realize successful electroweak baryogenesis. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license