Non-resonant collider signatures of a singlet-driven electroweak phase transition




Chen, Chien-Yi
Kozaczuk, Jonathan
Lewis, Ian M.

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Journal of High Energy Physics


We analyze the collider signatures of the real singlet extension of the Standard Model in regions consistent with a strong first-order electroweak phase transition and a singlet-like scalar heavier than the Standard Model-like Higgs. A definitive correlation exists between the strength of the phase transition and the trilinear coupling of the Higgs to two singlet-like scalars, and hence between the phase transition and non-resonant scalar pair production involving the singlet at colliders. We study the prospects for observing these processes at the LHC and a future 100 TeV pp collider, focusing particularly on double singlet production. We also discuss correlations between the strength of the electroweak phase transition and other observables at hadron and future lepton colliders. Searches for non-resonant singlet-like scalar pair production at 100 TeV would provide a sensitive probe of the electroweak phase transition in this model, complementing resonant di-Higgs searches and precision measurements. Our study illustrates a strategy for systematically exploring the phenomenologically viable parameter space of this model, which we hope will be useful for future work.


We thank David Curtin, Peisi Huang, Zhen Liu, Andrew Long, Stephen Martin, Jose Miguel No, Hiren Patel, Michael Ramsey-Musolf, and Graham Wilson for many illuminating discussions, suggestions and comments throughout the course of this work.


Beyond Standard Model, Cosmology of Theories beyond the SM, Higgs Physics, Thermal Field Theory


Chen, C.; Kozaczuk, J.; & Lewis, I.M. (2017). Non-resonant collider signatures of a singlet-driven electroweak phase transition. Journal of High Energy Physics, 2017(8), article 96. DOI: 10.1007/JHEP08(2017)096