scholarly journals The Critical Relationship Between Quarks and Quantum Chromodynamics.

2021 ◽  
Author(s):  
Ayan Nayak
Keyword(s):  
Quantum Chromodynamics ◽  
Particle Physics ◽  
Weak Interactions ◽  
Strong Interactions ◽  
Abelian Gauge ◽  
Physical Systems ◽  
Fundamental Particles ◽  
The Standard Model ◽  
The Relationship ◽  
Crucial Part

The objective of this abstract is to perform a systematic review of the critical relationship between quarks and quantum chromodynamics. The topic of this review abstract is the relationship between quarks and quantum chromodynamics. This relationship has been considered and still is considered one of the most groundbreaking connections in particle physics as it has allowed scientists to get a better view at “quarks”, an elementary particle with no substructure. Quantum Chromodynamics expresses and is the theory of strong interaction between quarks and gluons which are fundamental particles making up hadrons such as neutrons and protons. The theory plays a crucial part in the standard model of particle physics. The quantum field theory supporting quantum chromodynamics is a non-abelian gauge theory in which the lagrangian will not undergo change under local transformations. Quarks are one half of the base on which quantum chromodynamics is founded on. Quarks play a crucial role in the functioning of quantum chromodynamics as a whole and as such, affect other physical systems closely related to quantum chromodynamics such as strong interactions, weak interactions, and spin classification. Fully understanding the relation between Quarks and Quantum Chromodynamics will allow us to understand the true roles that quarks play in complex quantum systems.

Quantum chromodynamics: A non-Abelian gauge theory

2019 ◽  
pp. 209-236
Author(s):  
Jean Zinn-Justin
Keyword(s):  
Quantum Chromodynamics ◽  
Particle Physics ◽  
Gauge Theories ◽  
Brst Symmetry ◽  
Parallel Transport ◽  
Strong Interactions ◽  
Asymptotic Freedom ◽  
Abelian Gauge ◽  
Lattice Gauge ◽  
Colour Group

Chapter 13 is devoted to some aspects of quantum chromodynamics (QCD), the part of the Standard Model of particle physics responsible for strong interactions and based on an SU(3) gauge symmetry (the colour group) and gluon gauge fields. First, the geometry of non–Abelian gauge theories, based on parallel transport, is recalled. This leads naturally to the construction of lattice gauge theories with link variables and a plaquette action. The lattice model gives a hint of confinement. QCD is quantized in the temporal of Weyl gauge. Its renormalization involves the BRST symmetry. Its renormalization group properties with asymptotic freedom are emphasized. The infinite degeneracy of the semi–classical ground state can be associated to a winding number. Barrier penetration effects, related to the existence of instantons, lead to the existence of theta vacua and the problem of strong CP violation. Other issues considered are chiral symmetry and axial anomaly.

scholarly journals A bottom-up approach to the strong CP problem

2018 ◽  
Vol 33 (14n15) ◽  
pp. 1850088 ◽  
Author(s):  
J. L. Diaz-Cruz ◽  
W. G. Hollik ◽  
U. J. Saldana-Salazar
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Particle Physics ◽  
Weak Interactions ◽  
Theoretical Description ◽  
Strong Interactions ◽  
Top Down ◽  
Bottom Up ◽  
Elementary Particle Physics ◽  
The Standard Model

The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want to present a rather bottom-up perspective. The main problem seems to be how to achieve small CP violation in the strong interactions despite the large CP violation in weak interactions. In this paper, we show that with minimal assumptions on the structure of mass (Yukawa) matrices, they do not contribute to the strong CP problem and thus we can provide a pathway to a solution of the strong CP problem within the structures of the Standard Model and no extension at the electroweak scale is needed. However, to address the flavor puzzle, models based on minimal SU(3) flavor groups leading to the proposed flavor matrices are favored. Though we refrain from an explicit UV completion of the Standard Model, we provide a simple requirement for such models not to show a strong CP problem by construction.

scholarly journals The Standard Model vs. Physical Facts

2020 ◽  
pp. 1-12
Author(s):  
E. Comay
Keyword(s):  
Standard Model ◽  
Quantum Chromodynamics ◽  
Particle Physics ◽  
Scientific Theory ◽  
Electroweak Theory ◽  
Relevant Theory ◽  
The Standard Model ◽  
Physics Literature ◽  
Fundamental Physical ◽  
Physical Principles

Dynamical sectors of the Standard Model of particle physics are critically analyzed. It is proved thatquantum electrodynamics, quantum chromodynamics, and the electroweak theory are inconsistentwith fundamental physical principles. More than two examples apply to each of these theories, andany of these examples substantiate the unacceptable status of the relevant theory. Unfortunately,the mainstream particle physics literature ignores this situation and glorifies the Standard Modelas an excellent scientific theory.

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.

Electroweak Interactions and W, Z Boson Properties

2020 ◽  
Author(s):  
Maarten Boonekamp ◽  
Matthias Schott
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Top Quark ◽  
Quantum Electrodynamics ◽  
Weak Interactions ◽  
Higgs Field ◽  
Nuclear Research ◽  
Strong Interactions ◽  
Weak Boson ◽  
The Standard Model

With the huge success of quantum electrodynamics (QED) to describe electromagnetic interactions in nature, several attempts have been made to extend the concept of gauge theories to the other known fundamental interactions. It was realized in the late 1960s that electromagnetic and weak interactions can be described by a single unified gauge theory. In addition to the photon, the single mediator of the electromagnetic interaction, this theory predicted new, heavy particles responsible for the weak interaction, namely the W and the Z bosons. A scalar field, the Higgs field, was introduced to generate their mass. The discovery of the mediators of the weak interaction in 1983, at the European Center for Nuclear Research (CERN), marked a breakthrough in fundamental physics and opened the door to more precise tests of the Standard Model. Subsequent measurements of the weak boson properties allowed the mass of the top quark and of the Higgs Boson to be predicted before their discovery. Nowadays, these measurements are used to further probe the consistency of the Standard Model, and to place constrains on theories attempting to answer still open questions in physics, such as the presence of dark matter in the universe or unification of the electroweak and strong interactions with gravity.

Unification of Strong-Weak Interactions and Possible Unified Scheme of Four-Interactions

2020 ◽  
Vol 8 (5) ◽  
Author(s):  
Yi-Fang Chang
Keyword(s):  
Particle Physics ◽  
Short Range ◽  
Weak Interactions ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Strong Interactions ◽  
Main Character ◽  
Unified Theories ◽  
Three Dimensional Space

First, various known unified theories of interactions in particle physics are reviewed. Next, strong and weak interactions are all short-range, which should more be unified. Except different action ranges their main character is: strong interactions are attraction each other, and weak interactions are mutual repulsion and derive decay. We propose a possible method on their unification, whose coupling constants are negative and positive, respectively. Further, we propose a figure on the unification of the four basic interactions in three-dimensional space, and search some possible tests and predictions, for example, strong-weak interactions transform each other, some waves may be produced. Finally, based on the simplest unified gauge group GL(6,C) of four-interactions, a possible form of Lagrangian is researched. Some relations and equations of different interactions are discussed.

scholarly journals Parity-odd parton distribution functions from 𝜃-vacuum

2019 ◽  
Vol 34 (26) ◽  
pp. 1950145 ◽  
Author(s):  
Weihua Yang
Keyword(s):  
Quantum Chromodynamics ◽  
Parton Distribution ◽  
Vacuum State ◽  
High Energy ◽  
Distribution Functions ◽  
Point Of View ◽  
Strong Interactions ◽  
Parton Distribution Functions ◽  
Linear Superposition ◽  
Abelian Gauge

Quantum chromodynamics is a fundamental non-Abelian gauge theory of strong interactions. The physical quantum chromodynamics vacuum state is a linear superposition of the [Formula: see text]-vacua states with different topological numbers. Because of the configuration of the gauge fields, the tunneling events can induce the local parity-odd domains. Those interactions that occur in these domains can be affected by these effects. Considering the hadron (nucleon) system, we introduce the parity-odd parton distribution functions in order to describe the parity-odd structures inside the hadron in this paper. We obtain 8 parity-odd parton distribution functions at leading twist for spin-1/2 hadrons and present their properties. By introducing the parity-odd quark–quark correlator, we find the parity-odd effects vanish from the macroscopic point of view. In this paper, we consider the high energy semi-inclusive deeply inelastic scattering process to investigate parity-odd effects by calculating the spin asymmetries.

The Higgs boson: A major discovery and a problem

2019 ◽  
pp. 195-208
Author(s):  
Jean Zinn-Justin
Keyword(s):  
Higgs Boson ◽  
Particle Physics ◽  
Gauge Theories ◽  
Higgs Mechanism ◽  
Higgs Model ◽  
Fermion Mass ◽  
Simplified Models ◽  
Mass Generation ◽  
Abelian Gauge ◽  
The Standard Model

Chapter 12 describes the main steps in the construction of the electroweak component of the Standard Model of particle physics. The classical Abelian Landau–Ginzburg–Higgs mechanism is recalled, first introduced in the macroscopic description of a superconductor in a magnetic field. It is based on a combination of spontaneous symmetry breaking and gauge invariance. It can be generalized to non–Abelian gauge theories, quantized and renormalized. The recent discovery of the predicted Higgs boson has been the last confirmation of the validity of the model. Some aspects of the Higgs model and its renormalization group (RG) properties are illustrated by simplified models, a self–interacting Higgs model with the triviality issue, and the Gross–Neveu–Yukawa model with discrete chiral symmetry, which illustrates spontaneous fermion mass generation and possible RG flows.

The Standard Model (SM) of fundamental interactions

2021 ◽  
pp. 567-592
Author(s):  
Jean Zinn-Justin
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Nuclear Research ◽  
Strong Interactions ◽  
Higgs Particle ◽  
Fundamental Interactions ◽  
The Standard Model ◽  
Minimal Modification ◽  
Charge Conjugation Parity

The Standard Model (SM) 2020 of weak, electromagnetic and strong interactions, based on gauge symmetry and spontaneous symmetry breaking, describes all known fundamental interactions at the microscopic scale except gravity and, perhaps, interactions with dark matter. The SM model has been tested systematically in collider experiments, and in the case of strong interactions (quantum chromodynamics) also with numerical simulations. With the discovery in 2012 of the Higgs particle at the Large Hadron Collider (LHC) at the European Council for Nuclear Research (CERN), all particles of the SM have been identified, and most parameters have been measured. Still, the Higgs particle remains the most mysterious particle of the SM, since it is responsible for all the parameters of the SM except gauge couplings and since it leads to the fine-tuning problem. The discovery of its origin, and the precise study of its properties should be, in the future, one of the most important field of research in particle physics. Since we know now that the neutrinos have masses, the simplest extension of the SM implies Dirac neutrinos. With such a minimal modification, consistent so far (2020) with experimental data, the lepton and quark sectors have analogous structures: the lepton sector involves a mixing matrix, like the quark sector (three angles have been determined, the fourth charge conjugation parity (CP) violating angle is still unknown).

The Daya Bay Experiment and the Discovery of a New Type of Neutrino Oscillation

2012 ◽  
Vol 01 (02) ◽  
pp. 45-49
Author(s):  
Yifang Wang
Keyword(s):  
Standard Model ◽  
Experimental Evidence ◽  
Neutrino Oscillation ◽  
Particle Physics ◽  
Weak Interactions ◽  
Daya Bay ◽  
The Standard Model ◽  
New Type ◽  
Charged Leptons ◽  
The Universe

We know nowadays that the matter world we live in is made of 12 elementary particles, including 6 quarks, 3 charged leptons and 3 neutrinos. Among them, neutrinos are least known since they do not carry the electric charge and interact with others only weakly (often referred as the nuclear weak interactions). In the Standard Model of particle physics before 1998, neutrinos are considered as massless for simplicity and lack of experimental evidence. However, they are so abundant in the universe that their masses, even if tiny, will have significant impact to the particle physics, astrophysics and cosmology.

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