scholarly journals Electroweak-like baryogenesis with new chiral matter

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Kohei Fujikura ◽  
Keisuke Harigaya ◽  
Yuichiro Nakai ◽  
Ruoquan Wang
Keyword(s):  
Phase Transition ◽  
Gauge Symmetry ◽  
Cp Violation ◽  
Standard Model ◽  
Dipole Moments ◽  
Dark Matter Candidate ◽  
Lepton Asymmetry ◽  
First Order ◽  
The Standard Model ◽  
Concrete Realization

Abstract We propose a framework where a phase transition associated with a gauge symmetry breaking that occurs (not far) above the electroweak scale sets a stage for baryogenesis similar to the electroweak baryogenesis in the Standard Model. A concrete realization utilizes the breaking of SU(2)R× U(1)X→ U(1)Y. New chiral fermions charged under the extended gauge symmetry have nonzero lepton numbers, which makes the B − L symmetry anomalous. The new lepton sector contains a large flavor-dependent CP violation, similar to the Cabibbo-Kobayashi-Maskawa phase, without inducing sizable electric dipole moments of the Standard Model particles. A bubble wall dynamics associated with the first-order phase transition and SU(2)R sphaleron processes generate a lepton asymmetry, which is transferred into a baryon asymmetry via the ordinary electroweak sphaleron process. Unlike the Standard Model electroweak baryogenesis, the new phase transition can be of the strong first order and the new CP violation is not significantly suppressed by Yukawa couplings, so that the observed asymmetry can be produced. The model can be probed by collider searches for new particles and the observation of gravitational waves. One of the new leptons becomes a dark matter candidate. The model can be also embedded into a left-right symmetric theory to solve the strong CP problem.

Ring-diagram summations in the finite-temperature effective potential

1993 ◽  
Vol 71 (5-6) ◽  
pp. 227-236 ◽  
Author(s):  
M. E. Carrington
Keyword(s):  
Phase Transition ◽  
Standard Model ◽  
Effective Potential ◽  
Finite Temperature ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Ring Diagram ◽  
First Order Phase Transition ◽  
The Standard Model ◽  
The One

There has been much recent interest in the finite-temperature effective potential of the standard model in the context of the electroweak phase transition. We review the calculation of the effective potential with particular emphasis on the validity of the expansions that are used. The presence of a term that is cubic in the Higgs condensate in the one-loop effective potential appears to indicate a first-order electroweak phase transition. However, in the high-temperature regime, the infrared singularities inherent in massless models produce cubic terms that are of the same order in the coupling. In this paper, we discuss the inclusion of an infinite set of these terms via the ring-diagram summation, and show that the standard model has a first-order phase transition in the weak coupling expansion.

scholarly journals CP VIOLATION IN SUPERSYMMETRIC THEORIES

2003 ◽  
Vol 18 (10) ◽  
pp. 1697-1732 ◽  
Author(s):  
SHAABAN KHALIL
Keyword(s):  
Dipole Moment ◽  
Cp Violation ◽  
Standard Model ◽  
Electric Dipole ◽  
Dipole Moments ◽  
Neutron Electric Dipole Moment ◽  
Cp Asymmetry ◽  
Electric Dipole Moments ◽  
The Standard Model ◽  
Supersymmetric Theories

We review the present status of the CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the supersymmetric CP phases and show that only the scenarios with flavour-off-diagonal CP violation remain attractive. These scenarios require Hermitian Yukawa matrices which naturally arise in models with left–right symmetry or a SU(3) flavour symmetry. In this case, εK and ε′/ε can be saturated by a small non-universality of the soft scalar masses through the gluino and chargino contributions respectively. The model also predicts a strong correlation between A CP (b → sγ) and the neutron electric dipole moment. In this framework, the standard model gives a the leading contribution to the CP asymmetry in B → ψKS decay, while the dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint is set on the non-universality of this model by the recent BaBar and Belle measurements.

scholarly journals A chiral model for sterile neutrino

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Chun Liu ◽  
Yakefu Reyimuaji
Keyword(s):  
Dark Matter ◽  
Gauge Symmetry ◽  
Standard Model ◽  
Sterile Neutrino ◽  
Chiral Model ◽  
Dark Matter Candidate ◽  
Natural Explanation ◽  
The Standard Model

Abstract A model, which extends the standard model with a new chiral U(1)′ gauge symmetry sector, for the eV-mass sterile neutrino is constructed. It is basically fixed by anomaly free conditions. The lightness of the sterile neutrino has a natural explanation. As a by product, this model provides a WIMP-like dark matter candidate.

A REVIEW OF CP VIOLATION IN ATOMS

1993 ◽  
Vol 08 (02) ◽  
pp. 209-236 ◽  
Author(s):  
S.M. BARR
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Electric Dipole ◽  
Dipole Moments ◽  
Beyond The Standard Model ◽  
Electric Dipole Moments ◽  
The Standard Model ◽  
The Subject

The subject of atomic and molecular electric dipole moments is reviewed from the perspective of currently interesting theories of CP violation beyond the standard model.

scholarly journals Electroweak Baryogenesis with Anomalous Higgs Couplings

2016 ◽  
Vol 43 ◽  
pp. 1660200
Author(s):  
Archil Kobakhidze ◽  
Lei Wu ◽  
Jason Yue
Keyword(s):  
Phase Transition ◽  
Higgs Boson ◽  
Gauge Symmetry ◽  
Top Quark ◽  
Standard Model Particle ◽  
Particle Content ◽  
First Order ◽  
First Order Phase Transition ◽  
The Standard Model ◽  
First Order Phase

In non-linear realisation of the electroweak gauge symmetry, the LHC Higgs boson can be assumed to be a singlet under [Formula: see text]. In such scenario, the Standard Model particle content can be kept but new sets of couplings are allowed. We identify a range of anomalous Higgs cubic and the [Formula: see text]-violating Higgs-top quark couplings that leads to first order phase transition and successful baryogenesis at the electroweak scale.

scholarly journals Dark matter and baryogenesis from non-Abelian gauged lepton number

2017 ◽  
Vol 32 (19) ◽  
pp. 1730018 ◽  
Author(s):  
Bartosz Fornal
Keyword(s):  
Dark Matter ◽  
Gauge Symmetry ◽  
Simple Model ◽  
Standard Model ◽  
Gauge Group ◽  
Lepton Number ◽  
Dark Matter Candidate ◽  
The Standard Model ◽  
The Right ◽  
Standard Model Gauge Group

A simple model is constructed based on the gauge symmetry [Formula: see text], with only the leptons transforming nontrivially under [Formula: see text]. The extended symmetry is broken down to the Standard Model gauge group at TeV-scale energies. We show that this model provides a mechanism for baryogenesis via leptogenesis in which the lepton number asymmetry is generated by [Formula: see text] instantons. The theory also contains a dark matter candidate — the [Formula: see text] partner of the right-handed neutrino.

Scale-genesis — Origin of gravitational waves

2018 ◽  
Vol 33 (31) ◽  
pp. 1844019
Author(s):  
Jisuke Kubo
Keyword(s):  
Phase Transition ◽  
Standard Model ◽  
Gravitational Wave ◽  
Order Phase Transition ◽  
Energy Scale ◽  
Background Spectrum ◽  
First Order ◽  
First Order Phase Transition ◽  
The Standard Model ◽  
First Order Phase

We consider two realistic models for a scale invariant extension of the standard model, which couples with a hidden non-Abelian gauge sector. At energies around TeV, the hidden sector becomes strongly interacting, thereby generating a robust energy scale, which is transferred to the standard model sector, triggering the electroweak symmetry breaking. At a finite temperature, i.e. in the early Universe, the generation of the robust energy scale appears as a strong first-order phase transition. We calculate the gravitational wave background spectrum for both models, which is produced by the first-order phase transition. We compare the results with the experimental sensitivity of LISA and DECIGO and find the gravitational wave signal may be detected at DECIGO.

scholarly journals Mapping the shape of the scalar potential with gravitational waves

2019 ◽  
Vol 34 (33) ◽  
pp. 1950223
Author(s):  
Mikael Chala ◽  
Valentin V. Khoze ◽  
Michael Spannowsky ◽  
Philip Waite
Keyword(s):  
Phase Transition ◽  
Standard Model ◽  
Gravitational Wave ◽  
Order Phase Transition ◽  
Effective Potential ◽  
Scalar Potential ◽  
First Order ◽  
First Order Phase Transition ◽  
The Standard Model ◽  
First Order Phase

We study the dependence of the observable stochastic gravitational wave background induced by a first-order phase transition on the global properties of the scalar effective potential in particle physics. The scalar potential can be that of the Standard Model Higgs field, or more generally of any scalar field responsible for a spontaneous symmetry breaking in beyond-the-Standard-Model settings that provide for a first-order phase transition in the early universe. Characteristics of the effective potential include the relative depth of the true minimum [Formula: see text], the height of the barrier that separates it from the false one [Formula: see text] and the separation between the two minima in field space [Formula: see text], all at the bubble nucleation temperature. We focus on a simple yet quite general class of single-field polynomial potentials, with parameters being varied over several orders of magnitude. It is then shown that gravitational wave observatories such as aLIGO O5, BBO, DECIGO and LISA are mostly sensitive to values of these parameters in the region [Formula: see text]. Finally, relying on well-defined models and using our framework, we demonstrate how to obtain the gravitational wave spectra for potentials of various shapes without necessarily relying on dedicated software packages.

scholarly journals A new perspective on the electroweak phase transition in the Standard Model Effective Field Theory

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
José Eliel Camargo-Molina ◽  
Rikard Enberg ◽  
Johan Löfgren
Keyword(s):  
Field Theory ◽  
Phase Transition ◽  
Standard Model ◽  
Effective Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Quartic Coupling ◽  
Electroweak Phase Transition ◽  
First Order ◽  
The Standard Model

Abstract A first-order Electroweak Phase Transition (EWPT) could explain the observed baryon-antibaryon asymmetry and its dynamics could yield a detectable gravitational wave signature, while the underlying physics would be within the reach of colliders. The Standard Model, however, predicts a crossover transition. We therefore study the EWPT in the Standard Model Effective Field Theory (SMEFT) including dimension-six operators. A first-order EWPT has previously been shown to be possible in the SMEFT. Phenomenology studies have focused on scenarios with a tree-level barrier between minima, which requires a negative Higgs quartic coupling and a new physics scale low enough to raise questions about the validity of the EFT approach. In this work we stress that a first-order EWPT is also possible when the barrier between minima is generated radiatively, the quartic coupling is positive, the scale of new physics is higher, and there is good agreement with experimental bounds. Our calculation is done in a consistent, gauge-invariant way, and we carefully analyze the scaling of parameters necessary to generate a barrier in the potential. We perform a global fit in the relevant parameter space and explicitly find the points with a first-order transition that agree with experimental data. We also briefly discuss the prospects for probing the allowed parameter space using di-Higgs production in colliders.

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