scholarly journals Explaining Dark Matter Without New Physics?

2020 ◽  
Author(s):  
Stephane Maes
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Long Range ◽  
New Physics ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
New Particles

In a multi-fold universe, gravity emerges from entanglement through the multi-fold mechanisms. As a result, gravity-like effects appear in between entangled particles or regions. When applied to astrophysics, these effects are analogous to additional matter within or around galaxies. This way, we recover behaviors that match expected and observed effects when dark matter would be present or missing. No New Physics is introduced in terms of new particles beyond the Standard Model or modifying long range gravity: only the modeling of gravity as emerging from entanglement, in a multi-fold universe.

ASTROPARTICLE PHYSICS

2007 ◽  
Vol 22 (30) ◽  
pp. 5550-5560
Author(s):  
A. BETTINI
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Experimental Evidence ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Astroparticle Physics ◽  
The Standard Model ◽  
New Particles

Astroparticle is a very wide, expanding, sector of Physics; this report covers only a fraction of it complementing the plenary reports of Y. Takahashi and K. Inoue. I will focus, in particular, on the experimental evidence of new physics, beyond the Standard Model. Astroparticle and accelerator experiments will give complementary tools in the search of new particles, like those of the dark matter, and new fundamental fields, like the inflaton.

scholarly journals Search for Light New Physics atBFactories

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Bertrand Echenard
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
New Physics ◽  
Large Datasets ◽  
Higgs Bosons ◽  
The Standard Model ◽  
New Particles

Many extensions of the Standard Model include the possibility of light new particles, such as light Higgs bosons or dark matter candidates. These scenarios can be probed using the large datasets collected byBfactories, complementing measurements performed at the LHC. This paper summarizes recent searches for light new physics conducted by theBABARand Belle experiments.

scholarly journals Searches for new phenomena with the ATLAS detector

2020 ◽  
Vol 35 (34n35) ◽  
pp. 2044005
Author(s):  
Francesco Guescini
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
New Physics ◽  
Atlas Detector ◽  
Beyond The Standard Model ◽  
High Luminosity ◽  
Atlas Experiment ◽  
The Standard Model ◽  
New Phenomena

Many theories beyond the Standard Model predict new phenomena accessible by the Lhc. Searches for new physics are performed using the Atlas experiment at the Lhc focusing on exotic signatures that are predicted in several theories, excluding supersymmetry. The results of recent searches using 13 TeV data, with the exception of those for Dark Matter signatures, and their interplay and interpretation are presented. Prospects for searches at the High Luminosity Lhc are also discussed.

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 The SHiP experiment at CERN

2018 ◽  
Vol 182 ◽  
pp. 02016 ◽  
Author(s):  
Walter M. Bonivento
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Theoretical Models ◽  
Mass Range ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Beam Dump ◽  
Weakly Coupled ◽  
Physics Potential ◽  
The Standard Model

The discovery of the Higgs boson has fully confirmed the Standard Model of particles and fields. Nevertheless, there are still fundamental phenomena, like the existence of dark matter and the baryon asymmetry of the Universe, deserving an explanation that could come from the discovery of new particles. Searches for new physics with accelerators are performed at the LHC, looking for high massive particles coupled to matter with ordinary strength. A new experiment at CERN meant to search for very weakly coupled particles in the few GeV mass domain has been recently proposed. The existence of such particles, foreseen in different theoretical models beyond the Standard Model, is largely unexplored. A beam dump facility using high intensity 400 GeV protons is a copious source of such unknown particles in the GeV mass range. The beam dump is also a copious source of neutrinos and in particular it is an ideal source of tau neutrinos, the less known particle in the Standard Model. The neutrino detector can also search for dark matter through its scattering off the electrons. We report the physics potential of the SHiP experiment.

BEYOND THE STANDARD MODEL

2007 ◽  
Vol 22 (30) ◽  
pp. 5502-5512
Author(s):  
D. I. KAZAKOV
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Symmetry Breaking ◽  
New Physics ◽  
Electroweak Symmetry Breaking ◽  
Beyond The Standard Model ◽  
Electroweak Symmetry ◽  
The Standard Model ◽  
Recent Developments

Review of recent developments in attempts to go beyond the Standard Model is given. We concentrate on three main unresolved problems: mechanism of electroweak symmetry breaking, expected new physics at the TeV scale (mainly SUSY) and the origin of the Dark matter.

scholarly journals Heavy Chiral Fermions and Dark Matter

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Johan Alwall ◽  
Jusak Tandean
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Recent Observation ◽  
New Physics ◽  
Heavy Quarks ◽  
Fourth Generation ◽  
Beyond The Standard Model ◽  
Collider Phenomenology ◽  
Potential Implication ◽  
The Standard Model

Dark matter presents perhaps one of the most compelling direct indications of new physics beyond the standard model with three generations of fermions. In this paper, we survey several scenarios for dark matter in association with a fourth generation of chiral matter. The surveyed scenarios include stable heavy neutrino dark matter, composite dark matter consisting of stable heavy quarks, heavy quarks as mediators between the dark and visible sectors, and the four-generation standard model with the minimal addition of a stable real scalar field. We discuss the basic properties of the models, direct search constraints on their dark matter, and their collider phenomenology, as well as the possible effects of dark matter on the searches for a Higgs boson in the presence of four generations. We also comment on the potential implication of the recent observation of a Higgs-like new particle at the LHC.

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 Disentangling QCD and new physics in D → πℓ+ℓ−

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
Branching Ratios ◽  
New Physics ◽  
Operator Product ◽  
Beyond The Standard Model ◽  
Spectral Functions ◽  
The Standard Model ◽  
Model Independent ◽  
Weak Annihilation

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.

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