We study the dynamical freeze-in production of dark matter considering the electroweak phase transition history of the Universe. The kinematical thresholds of the decay and scattering processes for ...dark matter production can be altered by the temperature-dependent thermal masses of particles, which might lead to an enhancement or reduction of the dark matter relic abundance. The second-stage strongly first-order electroweak phase transition (SFOEWPT) triggered by the hidden scalars can be probed at colliders and gravitational wave detectors. Two-step SFOEWPT modified late decay feebly interacting massive particle dark matter is accomplished with a Dirac neutrino mass explanation in the scotogenic model.
A
bstract
In many particle physics models, domain walls can form during the phase transition process after the breakdown of the discrete symmetry. Utilizing the ℤ
3
symmetric complex singlet scalar ...extension of the Standard Model, we study the gravitational waves produced by the strongly first-order electroweak phase transition and the domain wall decay. The gravitational wave spectrum is of a typical two-peak shape. The high frequency peak corresponding to the strongly first-order electroweak phase transition is able to be probed by the future space-based interferometers, and the low frequency peak coming from the domain wall decay is far beyond the capability of the current Pulsar Timing Arrays, and future Square Kilometer Array.
With the assistance of a complex singlet, and an effective operator involving CP violations, the dark matter relic abundance and baryon asymmetry of the universe have been addressed simultaneously. ...We studied the electroweak baryogenesis mechanism systematically. The electroweak phase transition analysis indicates that the strong first order phase transition takes place by one-step or two-step type due to the dynamics of the energy gap between the electroweak vacuum and the vacuum of the complex singlet. The relation between the magnitude of baryon asymmetry of the universe and the phase transition type and strength has been explored in the framework of electroweak baryogenesis.
A
bstract
We study the superheavy dark matter (DM) scenario in an extended
B−L
model, where one generation of right-handed neutrino
ν
R
is the DM candidate. If there is a new lighter sterile neutrino ...that co-annihilate with the DM candidate, then the annihilation rate is exponentially enhanced, allowing a DM mass much heavier than the Griest-Kamionkowski bound (∼10
5
GeV). We demonstrate that a DM mass
M
νR
≳ 10
13
GeV can be achieved. Although beyond the scale of any traditional DM searching strategy, this scenario is testable via gravitational waves (GWs) emitted by the cosmic strings from the U(1)
B−L
breaking. Quantitative calculations show that the DM mass
O
(10
9
−10
13
GeV) can be probed by future GW detectors.
We study stochastic gravitational wave production and baryon number generation at electroweak phase transition with the two Higgs doublet models. The produced stochastic gravitational wave during the ...strongly first-order phase transition can be probed by future space-based interferometers. The nonlocal electroweak baryogenesis cannot address the observed Baryon asymmetry of the Universe successfully in the strongly first-order phase transition parameter spaces due to the CP violation phase is severely bounded by the electron electric dipole moment measurement ACMEII.
A
bstract
We study electroweak baryogenesis in the SO(6)/SO(5) composite Higgs model with the third generation quarks being embedded in the
20
′
representation of SO(6). The scalar sector contains ...one Higgs doublet and one real singlet, and their potential is given by the Coleman-Weinberg potential evaluated from the form factors of the lightest vector and fermion resonances. We show that the resonance masses at
O
1
∼
10
TeV
can generate a potential that triggers the strong first-order electroweak phase transition (SFOEWPT). The
CP
violating phase arising from the dimension-6 operator in the top sector is sufficient to yield the observed baryon asymmetry of the universe. The SFOEWPT parameter space is detectable at the future space-based detectors.
A
bstract
We consider the thermal effects into the evaluation of the dark matter production process. With the assistance of the right handed neutrinos, the freeze-in massive particle dark matter ...production history can be modified by the two-step phase transitions. The kinematic of decay/inverse decay or annihilation processes can be affected by the finite temperature effects as the Universe cools down. The history of the symmetry respected by the model can be revealed by the DM relic abundance evolution processes. The strong first order electroweak phase transition generated gravitational waves can be probed. The number of extra scalars for the Hierarchy problem can be probed through the Higgs off-shell searches at the LHC.
A
bstract
We study the strong first order electroweak phase transition (SFOEWPT) with the SO(6)
/
SO(5) composite Higgs model, whose scalar sector contains one Higgs doublet and one real singlet. Six ...benchmark models are built with fermion embeddings in
1
,
6
, and
15
of SO(6). We show that SFOEWPT cannot be triggered under the
minimal Higgs potential hypothesis
, which assumes the scalar potential is dominated by the form factors from the lightest composite resonances. To get a SFOEWPT, the contributions from local operators induced by physics above the cutoff scale are needed. We take the
6
+
6
model as an example to investigate the gravitational waves prediction and the related collider phenomenology.
A
bstract
We study the electroweak phase transition in the alignment limit of the CP-conserving two-Higgs-doublet model (2HDM) of Type I and Type II. The effective potential is evaluated at one-loop, ...where the thermal potential includes Daisy corrections and is reliably approximated by means of a sum of Bessel functions. Both 1-stage and 2-stage electroweak phase transitions are shown to be possible, depending on the pattern of the vacuum development as the Universe cools down. For the 1-stage case focused on in this paper, we analyze the properties of phase transition and discover that the field value of the electroweak symmetry breaking vacuum at the critical temperature at which the first order phase transition occurs is largely correlated with the vacuum depth of the 1-loop potential at zero temperature.
We demonstrate that a strong first order electroweak phase transition (SFOEWPT) in the 2HDM is achievable and establish benchmark scenarios leading to different testable signatures at colliders. In addition, we verify that an enhanced triple Higgs coupling (including loop corrections) is a typical feature of the SFOPT driven by the additional doublet. As a result, SFOEWPT might be able to be probed at the LHC and future lepton colliders through Higgs pair production.
The naturalness problem may be studied on the complex two-dimensional plane with the technique of dimensional regularization. The renormalization group equation of the Higgs mass on the plane ...suggests the Higgs mass approaches zero at the ultraviolet scale; the scale can be Planck scale when the top quark pole mass M sub(t) = 168 GeV The real issue of the naturalness problem in the sense of the Wilsonian renormalization group method is not about quadratic divergences but the rescaling effect. The Higgs mass can be considered to be one composed mass. All terms in the Lagrangian in this scenario are marginal terms and no relevant terms are left; thus, no rescaling effect exists to cause the naturalness problem. The renormalization group equation of the vacuum expectation value in the Landau gauge up to two-loop order is studied. Scale-dependent behavior of the composed Higgs mass shows that we can have one tiny Higgs mass at the high energy scale, even around the Planck scale, when M sub(t) < or = 170.7 GeV.
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