Complex scalar singlet dark matter: Vacuum stability and phenomenology

107

Abstract: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.

“…[42][43][44]. Given these considerations, our results are most reliable in the purple regions, where the perturbative expansion is clearly under control.…”

Section: Jhep08(2017)096mentioning

confidence: 67%

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

Chen

Kozaczuk

Lewis

2017

107

“…In our simple model we couple the additional scalar to the Standard Model through a Higgs portal [72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91] added to the effective potential of eq. (2.6),…”

Section: Jhep04(2015)022mentioning

confidence: 99%

The Higgs mass and the scale of new physics

Eichhorn

Gies

Jaeckel

et al. 2015

In view of the measured Higgs mass of 125 GeV, the perturbative renormalization group evolution of the Standard Model suggests that our Higgs vacuum might not be stable. We connect the usual perturbative approach and the functional renormalization group which allows for a straightforward inclusion of higher-dimensional operators in the presence of an ultraviolet cutoff. In the latter framework we study vacuum stability in the presence of higher-dimensional operators. We find that their presence can have a sizable influence on the maximum ultraviolet scale of the Standard Model and the existence of instabilities. Finally, we discuss how such operators can be generated in specific models and study the relation between the instability scale of the potential and the scale of new physics required to avoid instabilities.

“…In general, the couplings are also bounded from above in magnitude by perturbativity. For sufficiently large quartic couplings between the DM and the SM, running effects can push the model into a nonperturbative regime just above the weak scale [29][30][31].…”

Section: Cosmology a Electroweak Phase Transitionmentioning

confidence: 99%

Electroweak cogenesis

Cheung

Zhang

2013

We propose a simple renormalizable model of baryogenesis and asymmetric dark matter generation at the electroweak phase transition. Our setup utilizes the two Higgs doublet model plus two complex gauge singlets, the lighter of which is stable dark matter. The dark matter is charged under a global symmetry that is broken in the early universe but restored during the electroweak phase transition. Because the ratio of baryon and dark matter asymmetries is controlled by model parameters, the dark matter need not be light. Thus, new force carriers are unnecessary and the symmetric dark matter abundance can be eliminated via Higgs portal interactions alone. Our model places a rough upper bound on the dark matter mass, and has implications for direct detection experiments and particle colliders.