Beyond the Standard Model

2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Gordon Kane
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Model Theory ◽  
Beyond The Standard Model ◽  
The Standard Model

Spontaneous symmetry breaking has led physicists to possible solutions that extend the Standard Model theory to include gravity and dark matter candidates.

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 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 A global view of the off-shell Higgs portal

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Maximilian Ruhdorfer ◽  
Ennio Salvioni ◽  
Andreas Weiler
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Vector Boson ◽  
Effective Interaction ◽  
Goldstone Boson ◽  
High Energy ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Higgs Portal ◽  
First Time

We study for the first time the collider reach on the derivative Higgs portal, the leading effective interaction that couples a pseudo Nambu-Goldstone boson (pNGB) scalar Dark Matter to the Standard Model. We focus on Dark Matter pair production through an off-shell Higgs boson, which is analyzed in the vector boson fusion channel. A variety of future high-energy lepton colliders as well as hadron colliders are considered, including CLIC, a muon collider, the High-Luminosity and High-Energy versions of the LHC, and FCC-hh. Implications on the parameter space of pNGB Dark Matter are discussed. In addition, we give improved and extended results for the collider reach on the marginal Higgs portal, under the assumption that the new scalars escape the detector, as motivated by a variety of beyond the Standard Model scenarios.

scholarly journals Constraining extended scalar sectors at the LHC and beyond

2018 ◽  
Vol 33 (10n11) ◽  
pp. 1830007 ◽  
Author(s):  
Agnieszka Ilnicka ◽  
Tania Robens ◽  
Tim Stefaniak
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Standard Model ◽  
Parameter Space ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Doublet Model ◽  
Inert Doublet Model ◽  
Scalar Sector ◽  
Scalar Singlet

We give a brief overview of beyond the Standard Model (BSM) theories with an extended scalar sector and their phenomenological status in the light of recent experimental results. We discuss the relevant theoretical and experimental constraints, and show their impact on the allowed parameter space of two specific models: the real scalar singlet extension of the Standard Model (SM) and the Inert Doublet Model. We emphasize the importance of the LHC measurements, both the direct searches for additional scalar bosons, as well as the precise measurements of properties of the Higgs boson of mass 125 GeV. We show the complementarity of these measurements to electroweak and dark matter observables.

scholarly journals Hadronic and Hadron-Like Physics of Dark Matter

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 587 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Yu. Khlopov ◽  
Vladimir Kuksa ◽  
Nikolay Volchanskiy
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Weakly Interacting Massive Particles ◽  
Elementary Particles ◽  
Physical Basis ◽  
Beyond The Standard Model ◽  
Dark Matter Search ◽  
Weakly Interacting ◽  
The Standard Model ◽  
Massive Particles

The problems of simple elementary weakly interacting massive particles (WIMPs) appeal to extend the physical basis for nonbaryonic dark matter. Such extension involves more sophisticated dark matter candidates from physics beyond the Standard Model (BSM) of elementary particles. We discuss several models of dark matter, predicting new colored, hyper-colored or techni-colored particles and their accelerator and non-accelerator probes. The nontrivial properties of the proposed dark matter candidates can shed new light on the dark matter physics. They provide interesting solutions for the puzzles of direct and indirect dark matter search.

scholarly journals HIGGS MASS FROM A CASIMIR ENERGY INDUCED COSMOLOGICAL CONSTANT IN THE STANDARD MODEL

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1195-1201
Author(s):  
XIAO-GANG HE
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Spontaneous Symmetry Breaking ◽  
Particle Physics ◽  
Higgs Mass ◽  
Vacuum Energy ◽  
Casimir Energy ◽  
Renormalization Scale ◽  
The Standard Model

Casimir vacuum energy is divergent. It needs to be regularized. The regularization introduces a renormalization scale which may lead to a scale dependent cosmological constant. We show that the requirement of physical cosmological constant is renormalization scale independent provides important constraints on possible particle contents and their masses in particle physics models. In the Standard Model of strong and electroweak interactions, besides the Casimir vacuum energy there is also vacuum energy induced from spontaneous symmetry breaking. The requirement that the total vacuum energy to be scale independent dictates the Higgs mass to be [Formula: see text] where the summation is over fermions and Ni equals to 3 and 1 for quarks and leptons, respectively. The Higgs mass is predicted to be approximately 382 GeV.

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.

EFFECTS OF PAIRING CORRELATIONS ON THE ISOSPIN-SYMMETRY-BREAKING CORRECTION TO SUPER-ALLOWED 0+ → 0+ FERMI TRANSITIONS WITHIN THE HIGHER TAMM–DANCOFF APPROACH

2011 ◽  
Vol 20 (02) ◽  
pp. 274-280 ◽  
Author(s):  
JULIEN LE BLOAS ◽  
LUDOVIC BONNEAU ◽  
PHILIPPE QUENTIN ◽  
JOHANN BARTEL
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Electromagnetic Interaction ◽  
Sensitivity Study ◽  
Transition Matrix Element ◽  
Beyond The Standard Model ◽  
Isospin Symmetry ◽  
The Standard Model ◽  
Isospin Symmetry Breaking ◽  
Pairing Correlations

Super-allowed 0+ → 0+ Fermi transitions provide a test at low energy of the Standard Model of elementary interactions. The isospin-symmetry breaking due to the electromagnetic interaction at a nuclear level is a fundamental theoretical tool for the understanding of weak processes beyond the Standard Model. Within the Higher Tamm–Dancoff description of correlated nuclear states, we calculate the isospin-symmetry breaking correction δc to the Fermi transition matrix element. A sensitivity study on the T = 0 pairing correlations is carried out and some tests of model ingredients are performed. The obtained correction is of the order of 0.15~0.2% for plausible strengths in the T = 1 and T = 0 channels of the residual interaction. This is expected to constitute a lower bound.

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