scholarly journals Cosmic inflation in minimal $$U(1)_{B-L}$$ model: implications for (non) thermal dark matter and leptogenesis

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Debasish Borah ◽  
Suruj Jyoti Das ◽  
Abhijit Kumar Saha
Keyword(s):  
Dark Matter ◽  
Spontaneous Breaking ◽  
Minimal Coupling ◽  
Order Unity ◽  
Cosmic Inflation ◽  
Gauge Sector ◽  
Upper Limits ◽  
The Standard Model ◽  
The Universe

AbstractWe study the possibility of realising cosmic inflation, dark matter (DM), baryon asymmetry of the universe (BAU) and light neutrino masses in non-supersymmetric minimal gauged $$B-L$$ B - L extension of the standard model with three right handed neutrinos. The singlet scalar field responsible for spontaneous breaking of $$B-L$$ B - L gauge symmetry also plays the role of inflaton by virtue of its non-minimal coupling to gravity. While the lightest right handed neutrino is the DM candidate, being stabilised by an additional $$Z_2$$ Z 2 symmetry, we show by performing a detailed renormalisation group evolution (RGE) improved study of inflationary dynamics that thermal DM is generally overproduced due to insufficient annihilations through gauge and scalar portals. This happens due to strict upper limits obtained on gauge and other dimensionless couplings responsible for DM annihilation while assuming the non-minimal coupling to gravity to be at most of order unity. The non-thermal DM scenario is viable, with or without $$Z_2$$ Z 2 symmetry, although in such a case the $$B-L$$ B - L gauge sector remains decoupled from the inflationary dynamics due to tiny couplings. We also show that the reheat temperature predicted by the model prefers non-thermal leptogenesis with hierarchical right handed neutrinos while being consistent with other requirements.

scholarly journals Astrophysical aspects of milli-charged dark matter in a Higgs–Stueckelberg model

2015 ◽  
Vol 30 (18) ◽  
pp. 1550089 ◽  
Author(s):  
A. L. dos Santos ◽  
D. Hadjimichef
Keyword(s):  
Dark Matter ◽  
Weakly Interacting Massive Particles ◽  
Dark Sector ◽  
Minimal Coupling ◽  
Astrophysical Application ◽  
Gauge Sector ◽  
Dark Photon ◽  
The Standard Model ◽  
Vector Bosons ◽  
The Impact

An extension of the Standard Model (SM) is studied, in which two new vector bosons are introduced, a first boson Z' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A' field, in the dark sector of the model, remains massless and originates a dark photon γ'. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. In a Compton-like process, a photon scattered by a weakly interacting massive particles (WIMP) is converted into a dark photon. This process is studied, in an astrophysical application obtaining an estimate of the impact on stellar cooling of white dwarfs and neutron stars.

scholarly journals Heavy right-handed neutrino dark matter in left–right models

2017 ◽  
Vol 32 (15) ◽  
pp. 1740007 ◽  
Author(s):  
P. S. Bhupal Dev ◽  
Rabindra N. Mohapatra ◽  
Yongchao Zhang
Keyword(s):  
Dark Matter ◽  
Mass Range ◽  
Neutrino Masses ◽  
Seesaw Mechanism ◽  
Leptonic Sector ◽  
Active Neutrino ◽  
The Standard Model ◽  
The Stability ◽  
The Universe

We show that in a class of non-supersymmetric left–right extensions of the Standard Model (SM), the lightest right-handed neutrino (RHN) can play the role of thermal Dark Matter (DM) in the Universe for a wide mass range from TeV to PeV. Our model is based on the gauge group [Formula: see text] in which a heavy copy of the SM fermions is introduced and the stability of the RHN DM is guaranteed by an automatic [Formula: see text] symmetry present in the leptonic sector. In such models, the active neutrino masses are obtained via the type-II seesaw mechanism. We find a lower bound on the RHN DM mass of order TeV from relic density constraints, as well as a unitarity upper bound in the multi-TeV to PeV scale, depending on the entropy dilution factor. The RHN DM could be made long-lived by soft-breaking of the [Formula: see text] symmetry and provides a concrete example of decaying DM interpretation of the PeV neutrinos observed at IceCube.

scholarly journals What if ALP dark matter for the XENON1T excess is the inflaton

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Fuminobu Takahashi ◽  
Masaki Yamada ◽  
Wen Yin
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Decay Constant ◽  
The Standard Model ◽  
Electron Recoil ◽  
History Of ◽  
The Alps ◽  
The Right ◽  
The Universe

Abstract The recent XENON1T excess in the electron recoil data can be explained by anomaly-free axion-like particle (ALP) dark matter with mass mϕ = 2.3 ± 0.2 keV and the decay constant $$ {f}_{\phi }/{q}_e\simeq 2\times {10}^{10}\sqrt{\Omega_{\phi }/{\Omega}_{\mathrm{DM}}} $$ f ϕ / q e ≃ 2 × 10 10 Ω ϕ / Ω DM GeV. Intriguingly, the suggested mass and decay constant are consistent with the relation, $$ {f}_{\phi}\sim {10}^3\sqrt{m_{\phi }{M}_p} $$ f ϕ ∼ 10 3 m ϕ M p , predicted in a scenario where the ALP plays the role of the inflaton. This raises a possibility that the ALP dark matter responsible for the XENON1T excess also drove inflation in the very early universe. We study implications of the XENON1T excess for the ALP inflation and thermal history of the universe after inflation. We find that the successful reheating requires the ALP couplings to heavy fermions in the standard model, which results in an instantaneous reheating and subsequent thermalization of the ALPs. Then, an entropy dilution of $$ \mathcal{O} $$ O (10) is necessary to explain the XENON1T excess, which can be achieved by decays of the right-handed neutrinos.

scholarly journals Search for dark matter in association with an energetic photon in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Dark Matter ◽  
Transverse Momentum ◽  
Standard Model ◽  
Confidence Level ◽  
Axial Vector ◽  
Beyond The Standard Model ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
Upper Limits ◽  
The Standard Model

Abstract A search for dark matter is conducted in final states containing a photon and missing transverse momentum in proton-proton collisions at $$ \sqrt{s} $$ s = 13 TeV. The data, collected during 2015–2018 by the ATLAS experiment at the CERN LHC, correspond to an integrated luminosity of 139 fb−1. No deviations from the predictions of the Standard Model are observed and 95% confidence-level upper limits between 2.45 fb and 0.5 fb are set on the visible cross section for contributions from physics beyond the Standard Model, in different ranges of the missing transverse momentum. The results are interpreted as 95% confidence-level limits in models where weakly interacting dark-matter candidates are pair-produced via an s-channel axial-vector or vector mediator. Dark-matter candidates with masses up to 415 (580) GeV are excluded for axial-vector (vector) mediators, while the maximum excluded mass of the mediator is 1460 (1470) GeV. In addition, the results are expressed in terms of 95% confidence-level limits on the parameters of a model with an axion-like particle produced in association with a photon, and are used to constrain the coupling gaZγ of an axion-like particle to the electroweak gauge bosons.

scholarly journals The Search for Feebly Interacting Particles

2021 ◽  
Vol 71 (1) ◽  
pp. 279-313
Author(s):  
Gaia Lanfranchi ◽  
Maxim Pospelov ◽  
Philip Schuster
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Interaction Strength ◽  
New Physics ◽  
Fine Tuning ◽  
Experimental Program ◽  
Interacting Particles ◽  
Fundamental Physics ◽  
The Standard Model ◽  
The Universe

At the dawn of a new decade, particle physics faces the challenge of explaining the mystery of dark matter, the origin of matter over antimatter in the Universe, the apparent fine-tuning of the electroweak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves New Physics at mass scales comparable to that of familiar matter—below the GeV scale but with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and existing data may even provide hints of this possibility. Emboldened by the lessons of the LHC, a vibrant experimental program to discover such physics is underway, guided by a systematic theoretical approach that is firmly grounded in the underlying principles of the Standard Model. We give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs, and we focus in particular on accelerator-based experiments.

Interacting self-consistent system of spinor and gravitational fields

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040047
Author(s):  
Bijan Saha
Keyword(s):  
Spinor Field ◽  
Rapid Expansion ◽  
Minimal Coupling ◽  
Consistent System ◽  
Anisotropic Models ◽  
Gravitational Fields ◽  
Frw Model ◽  
Expansion Of The Universe ◽  
The Universe

Within the scope of simple cosmological models we have studied the role of spinor field in the evolution of the Universe when it is non-minimally coupled to the gravitational one. If the spinor field nonlinearity describes an ordinary matter such as radiation, the presence of non-minimality becomes essential and leads to the rapid expansion of the Universe in FRW model, but this is not the case for LRSBI model. If the spinor field nonlinearity describes a dark energy the role non-minimal coupling becomes insignificant in both isotropic and anisotropic models.

The Role of the Radial Orbit Instability in Dark Matter Halo Formation and Structure

2006 ◽  
Vol 2 (S235) ◽  
pp. 124-124
Author(s):  
J. M. Meyer ◽  
J. J. Dalcanton ◽  
T. R. Quinn ◽  
L. L. R. Williams ◽  
E. I. Barnes ◽  
...  
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Radial Orbit ◽  
Profile Changes ◽  
Analytic Models ◽  
The Universe ◽  
Scale Length

AbstractFor nearly a decade, N-body simulations have revealed a nearly universal dark matter density profile. This density profile appears to be robust to changes in the overall density of the universe and the underlying power spectrum. Despite its universality, however, the physical origin of this profile has not yet been well understood. Semi-analytic models have suggested that scale lengths in dark matter halos may be determined by the onset of the radial orbit instability. We have tested this theory using N-body simulations of collapsing dark matter halos. The resulting halo structures are prolate in shape, due to the mild aspect of the instability. We find that the radial orbit instability sets a scale length at which the velocity dispersion changes rapidly from isotropic to radially anisotropic. Preliminary analysis suggests that this scale length is proportional to the radius at which the density profile changes shape, as is the case in the semi-analytic models; however, the coefficient of proportionality is different by a factor of ~2. We conclude that the radial orbit instability may be a key physical mechanism responsible for the nearly universal profiles of simulated dark matter halos.

scholarly journals ELECTROWEAK UNIFICATION OF QUARKS AND LEPTONS IN A GAUGE GROUP SUC(3) × SU(4) × UX(1)

2012 ◽  
Vol 27 (21) ◽  
pp. 1250117 ◽  
Author(s):  
FAYYAZUDDIN
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Gauge Group ◽  
Lower Limit ◽  
Z Boson ◽  
Early Stage ◽  
Mass Scale ◽  
The Standard Model ◽  
Vector Bosons ◽  
The Universe

A model for electroweak unification of quarks and leptons, in a gauge group SUC(3) × SU(4) × UX(1) is constructed. The model requires, three generations of quarks and leptons which are replicas (mirror) of the standard quarks and leptons. The gauge group SU(4) × UX(1) is broken in such a way so as to reproduce standard model and to generate heavy masses for the vector bosons [Formula: see text], the leptoquarks and mirror fermions. It is shown lower limit on mass scale of mirror fermions is [Formula: see text], E- being the lightest mirror fermion coupled to Z boson. As the universe expands, the heavy matter is decoupled at an early stage of expansion and may be a source of dark matter. Leptoquarks in the model connect the standard model and mirror fermions. Baryon genesis in our universe implies antibaryon genesis in mirror universe.

scholarly journals Baryogenesis and dark matter in U(1) extensions

2017 ◽  
Vol 32 (15) ◽  
pp. 1740005 ◽  
Author(s):  
Wan-Zhe Feng ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Lepton Number ◽  
Current Data ◽  
Neutrino Masses ◽  
Neutrino Experiment ◽  
The Standard Model ◽  
Reactor Neutrino ◽  
The Universe ◽  
Neutrino Masses And Mixings

A brief review is given of some recent works where baryogenesis and dark matter have a common origin within the U(1) extensions of the Standard Model (SM) and of the minimal supersymmetric Standard Model (MSSM). The models considered generate the desired baryon asymmetry and the dark matter to baryon ratio. In one model, all of the fundamental interactions do not violate lepton number, and the total [Formula: see text] in the Universe vanishes. In addition, one may also generate a normal hierarchy of neutrino masses and mixings in conformity with the current data. Specifically, one can accommodate [Formula: see text] consistent with the data from Daya Bay reactor neutrino experiment.

scholarly journals Beyond the Standard Model at LEP

1991 ◽  
Vol 336 (1642) ◽  
pp. 247-259 ◽  
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Beyond The Standard Model ◽  
Grand Unified Theories ◽  
The Standard Model ◽  
Unified Theories ◽  
Massive Neutrinos ◽  
Supersymmetric Particles ◽  
The Universe

LEP data constrain severely many proposed extensions of the Standard Model. These include: massive neutrinos, which are now largely excluded as candidates for the dark matter of the Universe; supersymmetric particles, the lightest of which would still constitute detectable dark matter; technicolour, of which many favoured versions are now excluded by precision electroweak measurements; and grand unified theories, of which LEP data favour supersymmetric versions.

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