scholarly journals B - L CONSERVED BARYOGENESIS

2008 ◽  
Vol 23 (25) ◽  
pp. 2047-2051
Author(s):  
PEI-HONG GU ◽  
UTPAL SARKAR
Keyword(s):  
Baryon Asymmetry ◽  
Electroweak Scale ◽  
Lepton Asymmetry ◽  
The Universe

In the presence of anomaly induced sphaleron process, only a B - L asymmetry can be partially converted to the baryon asymmetry while any B + L asymmetry would be completely erased. Thus in any successful baryogenesis theories, B - L is usually violated above the electroweak scale to explain the observed matter–antimatter asymmetry of the universe. However, if any lepton asymmetry is not affected by the sphaleron processes, a B - L conserved theory can still realize the baryogenesis. We present here an SU(5) GUT realization of this scenario, which naturally accommodates small masses of Dirac neutrinos.

scholarly journals A dark clue to seesaw and leptogenesis in a pseudo-Dirac singlet doublet scenario with (non)standard cosmology

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Partha Konar ◽  
Ananya Mukherjee ◽  
Abhijit Kumar Saha ◽  
Sudipta Show
Keyword(s):  
Dark Matter ◽  
Thermal History ◽  
Direct Detection ◽  
Critical Role ◽  
Mass Term ◽  
Baryon Asymmetry ◽  
Dark Sector ◽  
Lepton Asymmetry ◽  
History Of ◽  
The Universe

Abstract We propose an appealing alternative scenario of leptogenesis assisted by dark sector which leads to the baryon asymmetry of the Universe satisfying all theoretical and experimental constraints. The dark sector carries a non minimal set up of singlet doublet fermionic dark matter extended with copies of a real singlet scalar field. A small Majorana mass term for the singlet dark fermion, in addition to the typical Dirac term, provides the more favourable dark matter of pseudo-Dirac type, capable of escaping the direct search. Such a construction also offers a formidable scope to radiative generation of active neutrino masses. In the presence of a (non)standard thermal history of the Universe, we perform the detailed dark matter phenomenology adopting the suitable benchmark scenarios, consistent with direct detection and neutrino oscillations data. Besides, we have demonstrated that the singlet scalars can go through CP-violating out of equilibrium decay, producing an ample amount of lepton asymmetry. Such an asymmetry then gets converted into the observed baryon asymmetry of the Universe through the non-perturbative sphaleron processes owing to the presence of the alternative cosmological background considered here. Unconventional thermal history of the Universe can thus aspire to lend a critical role both in the context of dark matter as well as in realizing baryogenesis.

BARYOGENESIS IN AN SO(10) GUT MODEL WITH PATI–SALAM INTERMEDIATE SYMMETRY

1998 ◽  
Vol 13 (19) ◽  
pp. 1539-1546
Author(s):  
F. BUCCELLA ◽  
O. PISANTI ◽  
L. ROSA
Keyword(s):  
Experimental Data ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Neutrino Oscillations ◽  
Baryon Asymmetry ◽  
Gauge Model ◽  
Electroweak Scale ◽  
Proton Lifetime ◽  
The Universe ◽  
Breaking Scale

The possibility of generating the observed baryon asymmetry of the universe in an SO(10) gauge model with spontaneous symmetry breaking pattern [Formula: see text] is studied. We find it possible to generate a [Formula: see text], converting the leptonic number produced at the B- L breaking scale via the B+L violating processes mediated by sphalerons at the electroweak scale. The resulting picture is tested against the limit coming from experimental data: proton lifetime and neutrino oscillations.

scholarly journals Leptogenesis in the Universe

2012 ◽  
Vol 2012 ◽  
pp. 1-59 ◽  
Author(s):  
Chee Sheng Fong ◽  
Enrico Nardi ◽  
Antonio Riotto
Keyword(s):  
Early Universe ◽  
Finite Temperature ◽  
Baryon Asymmetry ◽  
Quantum Corrections ◽  
Sterile Neutrinos ◽  
Lepton Asymmetry ◽  
The Universe

Leptogenesis is a class of scenarios in which the cosmic baryon asymmetry originates from an initial lepton asymmetry generated in the decays of heavy sterile neutrinos in the early Universe. We explain why leptogenesis is an appealing mechanism for baryogenesis. We review its motivations and the basic ingredients and describe subclasses of effects, like those of lepton flavours, spectator processes, scatterings, finite temperature corrections, the role of the heavier sterile neutrinos, and quantum corrections. We then address leptogenesis in supersymmetric scenarios, as well as some other popular variations of the basic leptogenesis framework.

scholarly journals Neutrino mass, leptogenesis and sterile neutrino dark matter in inverse seesaw framework

2021 ◽  
pp. 2150146
Author(s):  
Nayana Gautam ◽  
Mrinal Kumar Das
Keyword(s):  
Dark Matter ◽  
Neutrino Mass ◽  
Parameter Space ◽  
Sterile Neutrino ◽  
Baryon Asymmetry ◽  
Inverted Hierarchy ◽  
Lepton Asymmetry ◽  
The Standard Model ◽  
Active Mixing ◽  
The Universe

We study [Formula: see text] flavor symmetric inverse seesaw model which has the possibility of simultaneously addressing neutrino phenomenology, dark matter (DM) and baryon asymmetry of the universe (BAU) through leptogenesis. The model is the extension of the standard model by the addition of two (RH) neutrinos and three sterile fermions leading to a keV scale sterile neutrino DM and two pairs of quasi-Dirac states. The CP violating decay of the lightest quasi-Dirac pair present in the model generates lepton asymmetry which then converts to BAU. Thus, this model can provide a simultaneous solution for nonzero neutrino mass, DM content of the universes and the observed baryon asymmetry. The [Formula: see text] flavor symmetry in this model is augmented by additional [Formula: see text] symmetry to constrain the Yukawa Lagrangian. A detailed numerical analysis has been carried out to obtain DM mass, DM-active mixing as well as BAU both for normal hierarchy as well as inverted hierarchy. We try to correlate the two cosmological observables and found a common parameter space satisfying the DM phenomenology and BAU. The parameter space of the model is further constrained from the latest cosmological bounds on the observables.

scholarly journals Dynamo effects in gravity

2019 ◽  
Vol 127 ◽  
pp. 02009
Author(s):  
Boris Shevtsov
Keyword(s):  
Gravitational Constant ◽  
Nonlinear Oscillations ◽  
Big Bang ◽  
Baryon Asymmetry ◽  
System Of Equations ◽  
Fractal Structures ◽  
Expansion Of The Universe ◽  
The Big Bang ◽  
The Universe ◽  
Made In

Nonlinear oscillations in the dynamic system of gravitational and material fields are considered. The problems of singularities and caustics in gravity, expansion and baryon asymmetry of the Universe, wave prohibition of collapse into black holes, and failure of the Big Bang concept are discussed. It is assumed that the effects of the expansion of the Universe are coupling with the reverse collapse of dark matter. This hypothesis is used to substantiate the vortex and fractal structures in the distribution of matter. A system of equations is proposed for describing turbulent and fluctuation processes in gravitational and material fields. Estimates of the di usion parameters of such a system are made in comparison with the gravitational constant.

scholarly journals Dark Matter and the Baryon Asymmetry of the Universe

2006 ◽  
Vol 96 (4) ◽  
Author(s):  
Glennys R. Farrar ◽  
Gabrijela Zaharijas
Keyword(s):  
Dark Matter ◽  
Baryon Asymmetry ◽  
The Universe

Baryon asymmetry of the universe. A Monte Carlo study on the lattice

1987 ◽  
Vol 197 (1-2) ◽  
pp. 49-54 ◽  
Author(s):  
J. Ambjørn ◽  
M. Laursen ◽  
M.E. Shaposhnikov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Study ◽  
Baryon Asymmetry ◽  
The Universe

Construction of neutrino models with non-vanishing θ13 and leptogenesis

2015 ◽  
Vol 93 (12) ◽  
pp. 1561-1565
Author(s):  
Ng. K. Francis
Keyword(s):  
Neutrino Mass ◽  
Big Bang ◽  
Baryon Asymmetry ◽  
Daya Bay ◽  
Mass Model ◽  
Big Bang Nucleosynthesis ◽  
Great Discovery ◽  
Neutrino Mass Models ◽  
The Universe ◽  
Inflationary Models

We construct the neutrino mass models with non-vanishing θ13 and estimate the baryon asymmetry of the universe and subsequently derive the constraints on the inflaton mass and the reheating temperature after inflation. The great discovery of this decade, the detection of Higgs boson of mass 126 GeV and nonzero θ13, makes leptogenesis all the more exciting. Besides, the neutrino mass model is compatible with inflaton mass 1010–1013 GeV corresponding to reheating temperature TR ∼ 105–107 GeV to overcome the gravitino constraint in supersymmetry and big bang nucleosynthesis. When Daya Bay data θ13 ≈ 9° is included in the model, τ predominates over e and μ contributions, which are indeed a good sign. It is shown that neutrino mass models for a successful leptogenesis can be accommodated for a variety of inflationary models with a rather wide ranging inflationary scale.

The Lepton Asymmetry of the Universe

1982 ◽  
pp. 231-235
Author(s):  
Paul Langacker ◽  
Gino Segre ◽  
Sanjeev Soni
Keyword(s):  
Lepton Asymmetry ◽  
The Universe

scholarly journals Primordial black holes from the QCD epoch: linking dark matter, baryogenesis, and anthropic selection

2020 ◽  
Vol 501 (1) ◽  
pp. 1426-1439
Author(s):  
Bernard Carr ◽  
Sebastien Clesse ◽  
Juan García-Bellido
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Selection Effect ◽  
Mass Function ◽  
Baryon Asymmetry ◽  
Primordial Black Holes ◽  
Cosmological Horizon ◽  
Chandrasekhar Limit ◽  
The Universe ◽  
Characteristic Mass

ABSTRACT If primordial black holes (PBHs) formed at the quark-hadron epoch, their mass must be close to the Chandrasekhar limit, this also being the characteristic mass of stars. If they provide the dark matter (DM), the collapse fraction must be of order the cosmological baryon-to-photon ratio ∼10−9, which suggests a scenario in which a baryon asymmetry is produced efficiently in the outgoing shock around each PBH and then propagates to the rest of the Universe. We suggest that the temperature increase in the shock provides the ingredients for hotspot electroweak baryogenesis. This also explains why baryons and DM have comparable densities, the precise ratio depending on the size of the PBH relative to the cosmological horizon at formation. The observed value of the collapse fraction and baryon asymmetry depends on the amplitude of the curvature fluctuations that generate the PBHs and may be explained by an anthropic selection effect associated with the existence of galaxies. We propose a scenario in which the quantum fluctuations of a light stochastic spectator field during inflation generate large curvature fluctuations in some regions, with the stochasticity of this field providing the basis for the required selection. Finally, we identify several observational predictions of our scenario that should be testable within the next few years. In particular, the PBH mass function could extend to sufficiently high masses to explain the black hole coalescences observed by LIGO/Virgo.

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