Z' decay and dark matter relic density in a Stueckelberg extension of the Standard Model

2015 ◽  
Vol 336 (8-9) ◽  
pp. 900-904
Author(s):  
A. L. dos Santos ◽  
C. A. Z. Vasconcellos
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Dark Matter Relic Density ◽  
The Standard Model ◽  
Relic Density

scholarly journals DARK MATTER CANDIDATE FROM CONFORMALITY

2007 ◽  
Vol 22 (13) ◽  
pp. 931-937 ◽  
Author(s):  
P. H. FRAMPTON
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Weak Interaction ◽  
Gauge Theories ◽  
Dark Matter Candidate ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Relic Density ◽  
Baryonic Dark Matter

Abelian quiver gauge theories provide candidates for the conformality approach to physics beyond the standard model which possess novel cancellation mechanisms for quadratic divergences. A Z2 symmetry ( R parity) can be imposed and leads naturally to a dark matter candidate which is the Lightest Conformality Particle (LCP), a neutral spin-1 / 2 state with weak interaction annihilation cross-section, mass in the 100 GeV region and relic density of non-baryonic dark matter Ωdm which can be consistent with the observed value Ωdm≃0.24.

scholarly journals Dark matter, fine-tuning and (g-2)_{\mu} in the pMSSM

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Melissa van Beekveld ◽  
Wim Beenakker ◽  
Marrit Schutten ◽  
Jeremy De Wit
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Direct Detection ◽  
Fine Tuning ◽  
Dark Matter Relic Density ◽  
Depth Analysis ◽  
Relic Density ◽  
The Right ◽  
First Time

In this paper we perform for the first time an in-depth analysis of the spectra in the phenomenological supersymmetric Standard Model that simultaneously offer an explanation for the (g-2)_{\mu}(g−2)μ discrepancy \Delta a_{\mu}Δaμ, result in the right dark-matter relic density \Omega_{DM} h^2ΩDMh2 and are minimally fine-tuned. The resulting spectra may be obtained from [1]. To discuss the experimental exclusion potential for our models, we analyse the resulting LHC phenomenology as well as the sensitivity of dark-matter direct detection experiments to these spectra. We find that the latter type of experiments with sensitivity to the spin-dependent dark-matter–nucleon scattering cross section \sigma_{SD,p}σSD,p will probe all of our found solutions.

scholarly journals New physics explanations of aμ in light of the FNAL muon g − 2 measurement

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Peter Athron ◽  
Csaba Balázs ◽  
Douglas H. J. Jacob ◽  
Wojciech Kotlarski ◽  
Dominik Stöckinger ◽  
...  
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Average Deviation ◽  
Dark Matter Relic Density ◽  
Wide Range ◽  
The Standard Model ◽  
Parameter Ranges

Abstract The Fermilab Muon g −2 experiment recently reported its first measurement of the anomalous magnetic moment $$ {a}_{\mu}^{\mathrm{FNAL}} $$ a μ FNAL , which is in full agreement with the previous BNL measurement and pushes the world average deviation $$ \Delta {a}_{\mu}^{2021} $$ ∆ a μ 2021 from the Standard Model to a significance of 4.2σ. Here we provide an extensive survey of its impact on beyond the Standard Model physics. We use state-of-the-art calculations and a sophisticated set of tools to make predictions for aμ, dark matter and LHC searches in a wide range of simple models with up to three new fields, that represent some of the few ways that large ∆aμ can be explained. In addition for the particularly well motivated Minimal Supersymmetric Standard Model, we exhaustively cover the scenarios where large ∆aμ can be explained while simultaneously satisfying all relevant data from other experiments. Generally, the aμ result can only be explained by rather small masses and/or large couplings and enhanced chirality flips, which can lead to conflicts with limits from LHC and dark matter experiments. Our results show that the new measurement excludes a large number of models and provides crucial constraints on others. Two-Higgs doublet and leptoquark models provide viable explanations of aμ only in specific versions and in specific parameter ranges. Among all models with up to three fields, only models with chirality enhancements can accommodate aμ and dark matter simultaneously. The MSSM can simultaneously explain aμ and dark matter for Bino-like LSP in several coannihilation regions. Allowing under abundance of the dark matter relic density, the Higgsino- and particularly Wino-like LSP scenarios become promising explanations of the aμ result.

scholarly journals Neutrino Mass and the Higgs Portal Dark Matter in the ESSFSM

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Najimuddin Khan
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Neutrino Mass ◽  
Parameter Space ◽  
Direct Search ◽  
Type I ◽  
Seesaw Mechanism ◽  
The Standard Model ◽  
Relic Density ◽  
Higgs Portal

We extend the standard model with three right-handed singlet neutrinos and a real singlet scalar. We impose two Z2 and Z2′ symmetries. We explain the tiny neutrino mass-squared differences with two Z2- and Z2′-even right-handed neutrinos using type I seesaw mechanism. The Z2-odd fermion and the Z2′-odd scalar can both serve as viable dark matter candidates. We identify new regions in the parameter space which are consistent with relic density of the dark matter from recent direct search experiments LUX-2016 and XENON1T-2017 and LHC data.

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 Exothermic dark mesons in light of electron recoil excess at XENON1T

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Soo-Min Choi ◽  
Hyun Min Lee ◽  
Bin Zhu
Keyword(s):  
Dark Matter ◽  
Inelastic Scattering ◽  
Small Mass ◽  
Density Current ◽  
Flavor Symmetry ◽  
Color Group ◽  
Dark Sector ◽  
The Standard Model ◽  
Electron Recoil ◽  
Relic Density

Abstract We consider a novel mechanism to realize exothermic dark matter with dark mesons in the limit of approximate flavor symmetry in a dark QCD. We introduce a local dark U(1)′ symmetry to communicate between dark mesons and the Standard Model via Z′ portal by partially gauging the dark flavor symmetry with flavor-dependent charges for cancelling chiral anomalies in the dark sector. After the dark local U(1)′ is broken spontaneously by the VEV of a dark Higgs, there appear small mass splittings between dark quarks, consequently, leading to small split masses for dark mesons, required to explain the electron recoil excess in XENON1T by the inelastic scattering between dark mesons and electron. We propose a concrete benchmark model for split dark mesons based on SU(3)L× SU(3)R/SU(3)V flavor symmetry and SU(Nc) color group and show that there exists a parameter space making a better fit to the XENON1T data with two correlated peaks from exothermic processes and satisfying the correct relic density, current experimental and theoretical constraints.

scholarly journals Sterile Neutrinos as Dark Matter: Alternative Production Mechanisms in the Early Universe

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 264
Author(s):  
Daniel Boyanovsky
Keyword(s):  
Dark Matter ◽  
Distribution Function ◽  
Kinetic Equation ◽  
Standard Model ◽  
Early Universe ◽  
Quantum Kinetic Equation ◽  
Sterile Neutrinos ◽  
The Standard Model ◽  
Production Mechanisms ◽  
Freeze Out

We study various production mechanisms of sterile neutrinos in the early universe beyond and within the standard model. We obtain the quantum kinetic equations for production and the distribution function of sterile-like neutrinos at freeze-out, from which we obtain free streaming lengths, equations of state and coarse grained phase space densities. In a simple extension beyond the standard model, in which neutrinos are Yukawa coupled to a Higgs-like scalar, we derive and solve the quantum kinetic equation for sterile production and analyze the freeze-out conditions and clustering properties of this dark matter constituent. We argue that in the mass basis, standard model processes that produce active neutrinos also yield sterile-like neutrinos, leading to various possible production channels. Hence, the final distribution function of sterile-like neutrinos is a result of the various kinematically allowed production processes in the early universe. As an explicit example, we consider production of light sterile neutrinos from pion decay after the QCD phase transition, obtaining the quantum kinetic equation and the distribution function at freeze-out. A sterile-like neutrino with a mass in the keV range produced by this process is a suitable warm dark matter candidate with a free-streaming length of the order of few kpc consistent with cores in dwarf galaxies.

Extension of Standard Model in multi-spinor field formalism — Visible and dark sectors

2016 ◽  
Vol 31 (18) ◽  
pp. 1630027
Author(s):  
Ikuo S. Sogami
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Dark Sector ◽  
Quadratic Interaction ◽  
Inflationary Phase ◽  
The Standard Model ◽  
Visible Sector ◽  
Field Formalism ◽  
Main Component ◽  
Higgs Fields

With multi-spinor fields which behave as triple-tensor products of the Dirac spinors, the Standard Model is extended so as to embrace three families of ordinary quarks and leptons in the visible sector and an additional family of exotic quarks and leptons in the dark sector of our Universe. Apart from the gauge and Higgs fields of the Standard Model symmetry G, new gauge and Higgs fields of a symmetry isomorphic to G are postulated to exist in the dark sector. It is the bi-quadratic interaction between visible and dark Higgs fields that opens a main portal to the dark sector. Breakdowns of the visible and dark electroweak symmetries result in the Higgs boson with mass 125 GeV and a new boson which can be related to the diphoton excess around 750 GeV. Subsequent to a common inflationary phase and a reheating period, the visible and dark sectors follow weakly-interacting paths of thermal histories. We propose scenarios for dark matter in which no dark nuclear reaction takes place. A candidate for the main component of the dark matter is a stable dark hadron with spin 3/2, and the upper limit of its mass is estimated to be 15.1 GeV/c2.

scholarly journals DARK MATTER, AND ITS DARKNESS

2006 ◽  
Vol 15 (12) ◽  
pp. 2267-2278 ◽  
Author(s):  
D. V. AHLUWALIA-KHALILOVA
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cosmological Constant ◽  
Model Material ◽  
Representation Space ◽  
Spatial Curvature ◽  
The Standard Model ◽  
General Relativistic ◽  
Relativistic Description ◽  
Friedmann Robertson Walker

Assuming the validity of the general relativistic description of gravitation on astrophysical and cosmological length scales, we analytically infer that the Friedmann–Robertson–Walker cosmology with Einsteinian cosmological constant, and a vanishing spatial curvature constant, unambiguously requires a significant amount of dark matter. This requirement is consistent with other indications for dark matter. The same space–time symmetries that underlie the freely falling frames of Einsteinian gravity also provide symmetries which, for the spin one half representation space, furnish a novel construct that carries extremely limited interactions with respect to the terrestrial detectors made of the standard model material. Both the "luminous" and "dark" matter turn out to be residents of the same representation space but they derive their respective "luminosity" and "darkness" from either belonging to the sector with (CPT)2 = +𝟙, or to the sector with (CPT)2 = -𝟙.

Theoretical uncertainty of the supersymmetric dark matter relic density from scheme and scale variations

2016 ◽  
Vol 93 (11) ◽  
Author(s):  
J. Harz ◽  
B. Herrmann ◽  
M. Klasen ◽  
K. Kovařík ◽  
P. Steppeler
Keyword(s):  
Dark Matter ◽  
Theoretical Uncertainty ◽  
Dark Matter Relic Density ◽  
Relic Density
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