Gravitational wave, collider and dark matter signals from a scalar singlet electroweak baryogenesis

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.

“…extension of the SM have made use of simple analytic criteria for determining whether or not a first-order phase transition is possible at one loop [22,24,27] (see also ref. [54]).…”

Section: Jhep08(2017)096mentioning

confidence: 99%

“…refs. [22,24,27]. In our parametrization, this corresponds to the limit sin θ, b 3 → 0, and is thus a particular case of the model we are considering.…”

Section: A Strong Electroweak Phase Transition and The Triscalar Coupmentioning

confidence: 99%

Section: Jhep08(2017)096 1 Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Chen

Kozaczuk

Lewis

2017

107

“…We derive the classical equations of motion by variation of the action, and solve them numerically without further approximation. The initial condition is the vacuum state of the Higgs field, when the Higgs potential is simply 8) and where the field and momentum correlators are each given their zero-point fluctuations, sometimes referred to as the "just the half" initialisation [18][19][20]. We initialise only the unstable modes |k| ≤ µ.…”

Section: Jhep07(2017)010mentioning

confidence: 99%

“…Cold EWBG hence sidesteps the requirement of a first order phase transition, which is absent in the minimal Standard Model (at the physical Higgs mass), and increasingly constrained by experiment in simple extensions (for recent work, see for instance [6][7][8]). The scenario is very simple, and allows for straightforward first-principles numerical simulations of the entire baryogenesis process.…”

Section: Introductionmentioning

confidence: 99%

Simulations of Cold Electroweak Baryogenesis: finding the optimal quench time

Mou

Saffin

Tranberg

2017

Abstract:We revisit the numerical computation of the baryon asymmetry from Cold Electroweak Baryogenesis given the physical Higgs mass. We investigate the dependence of the asymmetry on the speed at which electroweak symmetry breaking takes place. The maximum asymmetry does not occur for arbitrarily fast quenches, but at quench times of about τ q 16 m −1 H , with no asymmetry created for quenches slower than τ q > 30 m −1 H . Curiously, we also find that the overall sign of the asymmetry depends on the quench time.

Probing the pre-BBN universe with gravitational waves from cosmic strings

Cui

Lewicki

Morrissey

et al. 2019

Self Cite

166

216

Many motivated extensions of the Standard Model predict the existence of cosmic strings. Gravitational waves originating from the dynamics of the resulting cosmic string network have the ability to probe many otherwise inaccessible properties of the early universe. In this study we show how the spectrum of gravitational waves from a cosmic string network can be used to test the equation of state of the early universe prior to Big Bang Nucleosynthesis (BBN). We also demonstrate that current and planned gravitational wave detectors such as LIGO, LISA, DECIGO/BBO, and ET/CE have the potential to detect signals of a non-standard pre-BBN equation of state and evolution of the early universe (e.g., early non-standard matter domination or kination domination) or new degrees of freedom active in the early universe beyond the sensitivity of terrestrial collider experiments and cosmic microwave background measurements. by reheating to a very hot radiation phase with temperature T TeV, which then cooled adiabatically until giving way to the recent matter and dark energy phases. We refer to this scenario, with only radiation domination (RD) over many orders of magnitude in temperature between reheating and the matter epoch, as the standard cosmology [11]. While this assumption is made frequently (and often implicitly), it has not been tested directly. Furthermore, non-standard cosmological scenarios with an extended period of domination by something other than radiation between inflation and BBN have strong motivation from many perspectives, including dark matter, axions, string compactification, reheating, and baryogenesis [10,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Testing the paradigm of pre-BBN cosmology is therefore of great significance in advancing our understanding of the universe.Gravitational waves (GWs) may provide a means of looking back in time beyond the BBN epoch and probing the universe in its very early stages [10,[27][28][29]. The observation of binary mergers by the LIGO/Virgo collaboration has already given further support to the ΛCDM cosmology [30], although -and this is important to the motivation of this work -the GWs observed were created only relatively recently. Opportunity to look even further back in time with GWs arises because, in contrast to photons, GWs freestream throughout the entire history of the cosmos. Indeed, GWs emitted as far back as inflation could potentially be detected by LIGO/Virgo [31] or proposed future detectors such as LISA [32], BBO/DECIGO [33], the Einstein Telescope (ET) [34, 35], and Cosmic Explorer (CE) [36].A stable and predictable source of primordial GWs is needed if they are to be used to test very early cosmology. Two promising and well-motivated potential sources are cosmic strings [37][38][39][40] and primordial inflation [41][42][43]. The application of inflationary GWs to probe the expansion history of the universe was studied in Refs. [44][45][46][47] and for non-standard histories in Refs. [48][49][50][51]. However, current limits from CM...