Electroweak phase transition and Higgs phenomenology in the Georgi-Machacek model

Understand

In this work, we perform the electroweak phase transition study with the Georgi-Machacek model.

• We investigate both the one-step and two-step strong first order electroweak phase transition (SFOEWPT).
• The SFOEWPT viable parameter spaces could be tested by the future 14 TeV LHC, HL-LHC, and ILC.
• The LHC Higgs signal strength measurements severely bound the SFOEWPT valid parameter spaces, a tinny region of the mixing angle between the neutral fields of the isospin-doublet and isospin-triplet scalars around $\alpha\sim 0$ can allow the two-step SFOEWPT to occur.