scholarly journals Electroweak Baryogenesis with Anomalous Higgs Couplings

2016 ◽  
Vol 43 ◽  
pp. 1660200
Author(s):  
Archil Kobakhidze ◽  
Lei Wu ◽  
Jason Yue

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.

2021 ◽  
Vol 36 (05) ◽  
pp. 2150024
Author(s):  
Shehu AbdusSalam ◽  
Mohammad Javad Kazemi ◽  
Layla Kalhor

For a cosmological first-order electroweak phase transition, requiring no sphaleron washout of baryon number violating processes leads to a lower bound on the strength of the transition. The velocity of the boundary between the phases, the so-called bubble wall, can become ultrarelativistic if the friction due to the plasma of particles is not sufficient to retard the wall’s acceleration. This bubble “runaway” should not occur if a successful baryon asymmetry generation due to the transition is required. Using Boedeker–Moore criterion for bubble wall runaway, within the context of an extension of the Standard Model of particle physics with a real gauge-single scalar field, we show that a nonrunaway transition requirement puts an upper bound on the strength of the first-order phase transition.


2018 ◽  
Vol 33 (31) ◽  
pp. 1844019
Author(s):  
Jisuke Kubo

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.


2019 ◽  
Vol 34 (33) ◽  
pp. 1950223
Author(s):  
Mikael Chala ◽  
Valentin V. Khoze ◽  
Michael Spannowsky ◽  
Philip Waite

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.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Aleksandr Azatov ◽  
Miguel Vanvlasselaer ◽  
Wen Yin

Abstract In this paper we present a novel mechanism for producing the observed Dark Matter (DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities can lead to the abundance of DM particles with masses much larger than the scale of the transition. We study this non-thermal production mechanism in the context of a generic phase transition and the electroweak phase transition. The application of the mechanism to the Higgs portal DM as well as the signal in the Stochastic Gravitational Background are discussed.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Kohei Fujikura ◽  
Keisuke Harigaya ◽  
Yuichiro Nakai ◽  
Ruoquan Wang

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.


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