Particle Physics

2017 ◽  
Author(s):  
Nicholas Manton ◽  
Nicholas Mee
Keyword(s):  
Particle Physics ◽  
Z Bosons ◽  
Theoretical Explanation ◽  
Particle Interactions ◽  
Quantum Field ◽  
Strong Force ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Klein Gordon

This chapter offers a brief introduction to quantum field theory and an outline of modern particle physics. The fundamental particles of the Standard Model are introduced. The quantization of fields is described, first the electromagnetic, then the Klein–Gordon and Dirac fields, followed by the prediction and discovery of antimatter. The importance of the action in QFT is outlined, along with its relationship to Feynman diagrams, particle interactions and QED. The path from the strong force to quarks, gluons and QCD is presented. The weak force is discussed, along with the subsequent discoveries of the neutrino and parity violation. The unified electroweak theory is described, including the Higgs mechanism. The discoveries of the W and Z bosons and the Higgs boson are discussed. Quark mixing and the CKM matrix are explained. The experimental determination of the number of generations is discussed. Neutrino oscillation experiments and their theoretical explanation are described.

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.

Concepts of Elementary Particle Physics

2019 ◽  
Author(s):  
Michael E. Peskin
Keyword(s):  
Elementary Particle ◽  
Particle Physics ◽  
Hadron Collider ◽  
Z Bosons ◽  
High Energy ◽  
High Energy Particle ◽  
Particle Interactions ◽  
Elementary Particle Physics ◽  
The Standard Model ◽  
Precision Study

This is a textbook of elementary particle physics whose goal is to explain the Standard Model of particle interactions. Part I introduces the basic concepts governing high-energy particle physics: elements of relativity and quantum field theory, the quark model of hadrons, methods for detection and measurement of elementary particles, methods for calculating predictions for observable quantitites. Part II builds up our understanding of the strong interaction from the key experiments to the formulation of Quantum Chromodynamics and its application to the description of evetns at the CERN Large Hadron Collider. Part III build up our understanding of the weak interaction from the key experiments to the formulation of spontaneously broken gauge theories. It then describes the tests and extensions of this theory, including the precision study of the W and Z bosons, CP violation, neutrino mass, and the Higgs boson.

scholarly journals Group Theoretical Derivation of Consistent Free Particle Theories

2020 ◽  
Vol 50 (9) ◽  
pp. 977-1007
Author(s):  
Giuseppe Nisticò
Keyword(s):  
Particle Physics ◽  
Free Particle ◽  
Canonical Quantization ◽  
Present Approach ◽  
Theoretical Derivation ◽  
Spin Particle ◽  
Elementary Particle Physics ◽  
Massive Spin ◽  
Klein Gordon

AbstractThe difficulties of relativistic particle theories formulated by means of canonical quantization, such as those of Klein–Gordon and Dirac, ultimately led theoretical physicists to turn to quantum field theory to model elementary particle physics. In order to overcome these difficulties, the theories of the present approach are developed deductively from the physical principles that specify the system, without making use of canonical quantization. For a free particle these starting assumptions are invariance of the theory and covariance of position with respect to Poincaré transformations. In pursuing the approach, the effectiveness of group theoretical methods is exploited. The coherent development of our program has shown that robust classes of representations of the Poincaré group, discarded by the known particle theories, can in fact be taken as bases for perfectly consistent theories. For massive spin zero particles, six inequivalent theories have been determined, two of which do not correspond to any of the current ones; all of these theories overcome the difficulties of Klein–Gordon one. The present lack of the explicit transformation properties of position with respect to boosts prevents the complete determination of non zero spin particle theories. In the past a particular form of these transformation properties was adopted by Jordan and Mukunda. We check its consistency within the present approach and find that for spin $$\frac{1}{2}$$ 1 2 particles there is only one consistent theory, which is unitarily related to Dirac’s; yet, once again, it requires classes of irreducible representations previously discarded.

scholarly journals THE FUTURE OF PARTICLE PHYSICS AS A NATURAL SCIENCE

1998 ◽  
Vol 13 (06) ◽  
pp. 863-886 ◽  
Author(s):  
FRANK WILCZEK
Keyword(s):  
Natural Science ◽  
Particle Physics ◽  
High Energy Physics ◽  
High Energy ◽  
Particle Interactions ◽  
Fundamental Particle ◽  
Current State ◽  
The Standard Model ◽  
Near Term ◽  
Energy Physics

In the first part of the paper, I give a low-resolution overview of the current state of particle physics — the triumph of the Standard Model and its discontents. I review and re-endorse the remarkably direct and (to me) compelling argument that existing data, properly interpreted, point toward a unified theory of fundamental particle interactions and toward low-energy supersymmetry as the near-term future of high energy physics as a natural science. I then attempt, as requested, some more "visionary" — i.e. even lower resolution — comments about the farther future. In that spirit, I emphasize the continuing importance of condensed matter physics as a source of inspiration and potential application, in particular for expansion of symmetry concepts, and of cosmology as a source of problems, applications, and perhaps ultimately limitations.

scholarly journals Magnetic monopoles in field theory and cosmology

2012 ◽  
Vol 370 (1981) ◽  
pp. 5705-5717 ◽  
Author(s):  
Arttu Rajantie
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Standard Model ◽  
Particle Physics ◽  
Magnetic Monopoles ◽  
Beyond The Standard Model ◽  
Quantum Field ◽  
Magnetic Systems ◽  
The Standard Model

The existence of magnetic monopoles is predicted by many theories of particle physics beyond the standard model. However, in spite of extensive searches, there is no experimental or observational sign of them. I review the role of magnetic monopoles in quantum field theory and discuss their implications for particle physics and cosmology. I also highlight their differences and similarities with monopoles found in frustrated magnetic systems.

Past, present and future of the muon g-2

2015 ◽  
Vol 39 ◽  
pp. 1560107
Author(s):  
A. E. Dorokhov ◽  
A. E. Radzhabov ◽  
A. S. Zhevlakov
Keyword(s):  
Quantum Electrodynamics ◽  
Particle Physics ◽  
Relativistic Quantum ◽  
Magnetic Moments ◽  
Structure Constant ◽  
New Physics ◽  
Fine Structure Constant ◽  
Measured Quantity ◽  
The Standard Model

The electron and muon anomalous magnetic moments (AMM) are measured in experiments and studied in the Standard Model (SM) with the highest precision accessible in particle physics. The comparison of the measured quantity with the SM prediction for the electron AMM provides the best determination of the fine structure constant. The muon AMM is more sensitive to the appearance of New Physics effects and, at present, there appears to be a three- to four-standard deviation between the SM and experiment. The lepton AMMs are pure relativistic quantum correction effects and therefore test the foundations of relativistic quantum field theory in general, and of quantum electrodynamics (QED) and SM in particular, with highest sensitivity. Special attention is paid to the studies of the hadronic contributions to the muon AMM which constitute the main source of theoretical uncertainties of the SM.

scholarly journals Form Factor Measurements at BESIII for an Improved Standard Model Prediction of the Muon g-2

2018 ◽  
Vol 46 ◽  
pp. 1860026
Author(s):  
Marco Destefanis
Keyword(s):  
Form Factor ◽  
Standard Model ◽  
Model Prediction ◽  
Particle Physics ◽  
Standard Model Prediction ◽  
Final States ◽  
Direct Measurements ◽  
The Standard Model ◽  
Data Driven Approach

The anomalous part of the magnetic moment of the muon, (g-2)[Formula: see text], allows for one of the most precise tests of the Standard Model of particle physics. We report on recent results by the BESIII Collaboration of exclusive hadronic cross section channels, such as the 2[Formula: see text], 3[Formula: see text], and 4[Formula: see text] final states. These measurements are of utmost importance for an improved calculation of the hadronic vacuum polarization contribution of (g-2)[Formula: see text], which currenty is limiting the overall Standard Model prediction of this quantity. BESIII has furthermore also intiatated a programme of spacelike transition form factor measurements, which can be used for a determination of the hadronic light-by-light contribution of (g-2)[Formula: see text] in a data-driven approach. These results are of relevance in view of the new and direct measurements of (g-2)[Formula: see text] as foreseen at Fermilab/USA and J-PARC/Japan.

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.

scholarly journals Electric–Magnetic Duality and the Dualized Standard Model

2003 ◽  
Vol 18 (supp02) ◽  
pp. 1-40 ◽  
Author(s):  
Sheung Tsun TSOU
Keyword(s):  
Standard Model ◽  
Atomic Physics ◽  
Particle Physics ◽  
Loop Space ◽  
Natural Explanation ◽  
The Third ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Dual Colour ◽  
Work Done

In these lectures I shall explain how a new-found nonabelian duality can be used to solve some outstanding questions in particle physics. The first lecture introduces the concept of electromagnetic duality and goes on to present its nonabelian generalization in terms of loop space variables. The second lecture discusses certain puzzles that remain with the Standard Model of particle physics, particularly aimed at nonexperts. The third lecture presents a solution to these problems in the form of the Dualized Standard Model, first proposed by Chan and the author, using nonabelian dual symmetry. The fundamental particles exist in three generations, and if this is a manifestation of dual colour symmetry, which by 't Hooft's theorem is necessarily broken, then we have a natural explanation of the generation puzzle, together with tested and testable consequences not only in particle physics, but also in astrophysics, nuclear and atomic physics. Reported is mainly work done in collaboration with Chan Hong-Mo, and also various parts with Peter Scharbach, Jacqueline Faridani, José Bordes, Jakov Pfaudler, Ricardo Gallego severally.

scholarly journals From Hot Beams to Trapped Ultracold Molecules: Motivations, Methods and Future Directions

2021 ◽  
pp. 491-516
Author(s):  
N. J. Fitch ◽  
M. R. Tarbutt
Keyword(s):  
Laser Cooling ◽  
Electric Dipole ◽  
Particle Physics ◽  
Dipole Moments ◽  
Current Status ◽  
Past Century ◽  
Beyond The Standard Model ◽  
Ultracold Molecules ◽  
Fundamental Particles ◽  
The Standard Model

AbstractOver the past century, the molecular beam methods pioneered by Otto Stern have advanced our knowledge and understanding of the world enormously. Stern and his colleagues used these new techniques to measure the magnetic dipole moments of fundamental particles with results that challenged the prevailing ideas in fundamental physics at that time. Similarly, recent measurements of fundamental electric dipole moments challenge our present day theories of what lies beyond the Standard Model of particle physics. Measurements of the electron’s electric dipole moment (eEDM) rely on the techniques invented by Stern and later developed by Rabi and Ramsey. We give a brief review of this historical development and the current status of eEDM measurements. These experiments, and many others, are likely to benefit from ultracold molecules produced by laser cooling. We explain how laser cooling can be applied to molecules, review recent progress in this field, and outline some eagerly anticipated applications.

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