Global Electroweak Symmetric Vacuum

Bai, Yang; Lee, Seung J.; Son, Minho; Ye, Fang

doi:10.48550/arxiv.2103.09819

“…We have first studied the phenomenon of EW symmetry non-restoration, which has recently regained attention in the literature [34][35][36]99]. We have shown that in the N2HDM this behaviour is driven by contributions from the resummation of daisy diagrams.…”

Section: Discussionmentioning

confidence: 99%

Fate of electroweak symmetry in the early Universe: non-restoration and trapped vacua in the N2HDM

Biekötter

¹

,

Heinemeyer

²

,

No

³

et al. 2021

J. Cosmol. Astropart. Phys.

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Extensions of the Higgs sector of the Standard Model allow for a rich cosmological history around the electroweak scale. We show that besides the possibility of strong firstorder phase transitions, which have been thoroughly studied in the literature, also other important phenomena can occur, like the non-restoration of the electroweak symmetry or the existence of vacua in which the Universe becomes trapped, preventing a transition to the electroweak minimum. Focusing on the next-to-minimal two-Higgs-doublet model (N2HDM) of type II and taking into account the existing theoretical and experimental constraints, we identify the scenarios of electroweak symmetry non-restoration, vacuum trapping and first-order phase transition in the thermal history of the Universe. We analyze these phenomena and in particular their relation to each other, and discuss their connection to the predicted phenomenology of the N2HDM at the LHC. Our analysis demonstrates that the presence of a global electroweak minimum of the scalar potential at zero temperature does not guarantee that the corresponding N2HDM parameter space will be physically viable: the existence of a critical temperature at which the electroweak phase becomes the deepest minimum is not sufficient for a transition to take place, necessitating an analysis of the tunnelling probability to the electroweak minimum for a reliable prediction of the thermal history of the Universe.

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“…We have first studied the phenomenon of EW symmetry non-restoration, which has recently regained attention in the literature [34][35][36]94]. We have shown that in the N2HDM this behaviour is driven by contributions from the resummation of daisy diagrams.…”

Section: Discussionmentioning

confidence: 99%

Fate of electroweak symmetry in the early Universe: Non-restoration and trapped vacua in the N2HDM

Biekötter,

Heinemeyer,

No

et al. 2021

Preprint

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Extensions of the Higgs sector of the Standard Model allow for a rich cosmological history around the electroweak scale. We show that besides the possibility of strong firstorder phase transitions, which have been thoroughly studied in the literature, also other important phenomena can occur, like the non-restoration of the electroweak symmetry or the existence of vacua in which the Universe becomes trapped, preventing a transition to the electroweak minimum. Focusing on the next-to-minimal two-Higgs-doublet model (N2HDM) of type II and taking into account the existing theoretical and experimental constraints, we identify the scenarios of electroweak symmetry non-restoration, vacuum trapping and first-order phase transition in the thermal history of the Universe. We analyze these phenomena and in particular their relation to each other, and discuss their connection to the predicted phenomenology of the N2HDM at the LHC. Our analysis demonstrates that the presence of a global electroweak minimum of the scalar potential at zero temperature does not guarantee that the corresponding N2HDM parameter space will be physically viable: the existence of a critical temperature at which the electroweak phase becomes the deepest minimum is not sufficient for a transition to take place, necessitating an analysis of the tunnelling probability to the electroweak minimum for a reliable prediction of the thermal history of the Universe.

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“…The general concept of symmetry non-restoration (SNR) was first explored by Weinberg [1] and then expanded upon in [2][3][4][5][6][7][8][9][10][11][12][13]. Recently, scenarios of SNR for the electroweak sector, and the associated phenomenological observables, have become a topic of investigation [14][15][16][17][18][19][20][21]. Electroweak SNR is of special interest in the context of certain baryogenesis scenarios [22].…”

Section: Introductionmentioning

confidence: 99%

Electroweak Symmetry Non-Restoration from Dark Matter

Matsedonskyi,

Unwin,

Wang

2021

Preprint

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Restoration of the electroweak symmetry at temperatures around the Higgs mass is linked to tight phenomenological constraints on many baryogenesis scenarios. A potential remedy can be found in mechanisms of electroweak symmetry non-restoration (SNR), in which symmetry breaking is extended to higher temperatures due to new states with couplings to the Standard Model. Here we show that, in the presence of a second Higgs doublet, SNR can be realized with only a handful of new fermions which can be identified as viable dark matter candidates consistent with all current observational constraints. The competing requirements on this class of models allow for SNR at temperatures up to ∼TeV, and imply the presence of sub-TeV new physics with sizable interactions with the Standard Model. As a result this scenario is highly testable with signals in reach of next-generation collider and dark matter direct detection experiments.

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Global Electroweak Symmetric Vacuum

Cited by 3 publications

References 44 publications

Fate of electroweak symmetry in the early Universe: non-restoration and trapped vacua in the N2HDM

Fate of electroweak symmetry in the early Universe: non-restoration and trapped vacua in the N2HDM

Fate of electroweak symmetry in the early Universe: Non-restoration and trapped vacua in the N2HDM

Electroweak Symmetry Non-Restoration from Dark Matter

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