scholarly journals Beyond the standard model of particle physics

2016 ◽  
Vol 374 (2075) ◽  
pp. 20150259 ◽  
Author(s):  
T. S. Virdee
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
Final Theory ◽  
Fundamental Particles ◽  
Open Questions ◽  
The Standard Model ◽  
The Status ◽  
Fundamental Forces

The Large Hadron Collider (LHC) at CERN and its experiments were conceived to tackle open questions in particle physics. The mechanism of the generation of mass of fundamental particles has been elucidated with the discovery of the Higgs boson. It is clear that the standard model is not the final theory. The open questions still awaiting clues or answers, from the LHC and other experiments, include: What is the composition of dark matter and of dark energy? Why is there more matter than anti-matter? Are there more space dimensions than the familiar three? What is the path to the unification of all the fundamental forces? This talk will discuss the status of, and prospects for, the search for new particles, symmetries and forces in order to address the open questions. This article is part of the themed issue ‘Unifying physics and technology in light of Maxwell's equations’.

Forces of the World Unite!

2019 ◽  
pp. 54-63
Author(s):  
Nicholas Mee
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Particle Accelerators ◽  
Strong Force ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Small Collection ◽  
Electroweak Force ◽  
Structure Of Matter

The structure of matter and the forces that are important in particle physics are now understood in terms of the Standard Model, which is currently being tested at the Large Hadron Collider (LHC). Since the 1930s, physicists have used particle accelerators to investigate the structure of matter. Three forces are important in particle interactions, the strong force, the weak force and the electromagnetic force. The weak and electromagnetic forces are now recognized as two components of a unified electroweak force. The strong force and the electroweak force act on a small collection of fundamental particles that include quarks, the subcomponents of protons, neutrons and many other particles. The final missing piece of the Standard Model, the Higgs boson, was discovered by the LHC in 2012.

scholarly journals Synthesis on Heavy Higgs from the Standard Model to 2HDM and Beyond

2020 ◽  
Vol 18 ◽  
pp. 110-142
Author(s):  
Abdeljalil Habjia
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Sections ◽  
Particle Physics ◽  
Hadron Collider ◽  
Signal Strength ◽  
Beyond The Standard Model ◽  
Decay Channels ◽  
Higgs Decay ◽  
The Standard Model

In the context of particle physics, within the ATLAS and CMS experiments at large hadron collider (LHC), this work presents the discussion of the discovery of a particle compatible with the Higgs boson by the combination of several decay channels, with a mass of the order of 125.5 GeV. With increased statistics, that is the full set of data collected by the ATLAS and CMS experiments at LHC ( s1/2 = 7GeV and s1/2 = 8GeV ), the particle is also discovered individually in the channel h-->γγ with an observed significance of 5.2σ and 4.7σ, respectively. The analysis dedicated to the measurement of the mass mh and signal strength μ which is defined as the ratio of σ(pp --> h) X Br(h-->X) normalized to its Standard Model where X = WW*; ZZ*; γγ ; gg; ff. The combined results in h-->γγ channel gave the measurements: mh = 125:36 ± 0:37Gev, (μ = 1:17 ± 0:3) and the constraint on the width Γ(h) of the Higgs decay of 4.07 MeV at 95%CL. The spin study rejects the hypothesis of spin 2 at 99 %CL. The odd parity (spin parity 0- state) is excluded at more than 98%CL. Within the theoretical and experimental uncertainties accessible at the time of the analysis, all results: channels showing the excess with respect to the background-only hypothesis, measured mass and signal strength, couplings, quantum numbers (JPC), production modes, total and differential cross-sections, are compatible with the Standard Model Higgs boson at 95%CL. Although the Standard Model is one of the theories that have experienced the greatest number of successes to date, it is imperfect. The inability of this model to describe certain phenomena seems to suggest that it is only an approximation of a more general theory. Models beyond the Standard Model, such as 2HDM, MSSM or NMSSM, can compensate some of its limitations and postulate the existence of additional Higgs bosons.

scholarly journals The Standard Model

2012 ◽  
Vol 370 (1961) ◽  
pp. 805-817 ◽  
Author(s):  
Tara Shears
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Particle Physics ◽  
Experimental Tests ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Fundamental Forces ◽  
Physics Experiments

The Standard Model is the theory used to describe the interactions between fundamental particles and fundamental forces. It is remarkably successful at predicting the outcome of particle physics experiments. However, the theory has not yet been completely verified. In particular, one of the most vital constituents, the Higgs boson, has not yet been observed. This paper describes the Standard Model, the experimental tests of the theory that have led to its acceptance and its shortcomings.

LOOKING FORWARD TO THE LARGE HADRON COLLIDER

2007 ◽  
Vol 22 (27) ◽  
pp. 5039-5051
Author(s):  
GEOFFREY N. TAYLOR
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
General Purpose ◽  
Beyond The Standard Model ◽  
Standard Model Higgs Boson ◽  
The Standard Model ◽  
The Status ◽  
Ambitious Program

In this paper an overview of the Large Hadron Collider program and status is given, including a brief description of the scientific background from which this ambitious program evolved. The emphasis is on the status of the Standard Model Higgs Boson, searches for which are the key component of the LHC program. A description of the ATLAS one of the two large general purpose experiments designed to detect evidence for the Higgs Boson and other data of interest to searches for physics beyond the standard model.

scholarly journals Outstanding questions: physics beyond the Standard Model

2012 ◽  
Vol 370 (1961) ◽  
pp. 818-830 ◽  
Author(s):  
John Ellis
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
The Difference ◽  
The Universe

The Standard Model of particle physics agrees very well with experiment, but many important questions remain unanswered, among them are the following. What is the origin of particle masses and are they due to a Higgs boson? How does one understand the number of species of matter particles and how do they mix? What is the origin of the difference between matter and antimatter, and is it related to the origin of the matter in the Universe? What is the nature of the astrophysical dark matter? How does one unify the fundamental interactions? How does one quantize gravity? In this article, I introduce these questions and discuss how they may be addressed by experiments at the Large Hadron Collider, with particular attention to the search for the Higgs boson and supersymmetry.

scholarly journals RARE DECAYS AND CP VIOLATION BEYOND THE STANDARD MODEL

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1738-1749 ◽  
Author(s):  
LUCA SILVESTRINI
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Rare Decays ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Unitarity Triangle ◽  
Minimal Flavour Violation ◽  
The Standard Model ◽  
The Status ◽  
Flavour Violation

We review the status of rare decays and CP violation in extensions of the Standard Model. We analyze the determination of the unitarity triangle and the model-independent constraints on new physics that can be derived from this analysis. We find stringent bounds on new contributions to [Formula: see text] and [Formula: see text] mixing, pointing either to models of minimal flavour violation or to models with new sources of flavour and CP violation in b → s transitions. We discuss the status of the universal unitarity triangle in minimal flavour violation, and study rare decays in this class of models. We then turn to supersymmetric models with nontrivial mixing between second and third generation squarks, discuss the present constraints on this mixing and analyze the possible effects on CP violation in b → s nonleptonic decays and on [Formula: see text] mixing. We conclude presenting an outlook on Lepton-Photon 2009.

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