Dimensional reduction of the Standard Model coupled to a new singlet scalar field
Tomáš Brauner (Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway); Tuomas Tenkanen (Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, Helsinki, Finland); Anders Tranberg (Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway); Aleksi Vuorinen (Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, Helsinki, Finland); David Weir (Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway, Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014, Helsinki, Finland)
We derive an effective dimensionally reduced theory for the Standard Model augmented by a real singlet scalar. We treat the singlet as a superheavy field and integrate it out, leaving an effective theory involving only the Higgs and SU(2) L × U(1) Y gauge fields, identical to the one studied previously for the Standard Model. This opens up the possibility of efficiently computing the order and strength of the electroweak phase transition, numerically and nonperturbatively, in this extension of the Standard Model. Understanding the phase diagram is crucial for models of electroweak baryogenesis and for studying the production of gravitational waves at thermal phase transitions.
