"Quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons."
Applies QFT to describe strong interactions, the behavior of quarks and gluons, and the confinement of quarks within hadrons.
Quantum Mechanics: Understanding the basic principles of quantum mechanics is essential to understanding quantum chromodynamics. Quantum mechanics deals with the behavior of particles at the atomic and subatomic level, and it forms the basis for quantum field theory.
Quantum Field Theory: Quantum field theory is a mathematical framework used to study the behavior of subatomic particles. It describes the interaction between particles in terms of quantum fields, which are mathematical objects that describe the properties of particles at different points in space and time.
Gauge Invariance: Gauge invariance is a symmetry principle that plays a crucial role in quantum field theory. It is used to ensure that the theory is consistent and that the equations of motion for particles are valid under all possible conditions.
Renormalization: Renormalization is a technique used in quantum field theory to remove divergences that arise in the calculations of certain physical quantities. These divergences can be a result of the infinite degrees of freedom that arise in the quantum theory.
Parton Model: The parton model is a model used to describe the behavior of hadrons, which are composite particles made up of quarks and gluons. The model assumes that the interactions between the quarks and gluons inside the hadron can be treated as independent partons that carry a fraction of the hadron's momentum.
Asymptotic Freedom: Asymptotic freedom is a property of quantum chromodynamics that describes how the strength of the strong force decreases as the distance between particles increases. This property is responsible for the phenomenon of quark confinement, which prevents quarks from existing outside of hadrons.
Quark Confinement: Quark confinement is the phenomenon that prevents quarks from existing outside of hadrons. It is a consequence of the strong force becoming infinitely strong at short distances, which prevents quarks from separating from each other.
Lattice QCD: Lattice QCD is a numerical technique used to study quantum chromodynamics on a discrete lattice of spacetime. It allows researchers to perform non-perturbative calculations that are not feasible using other analytical techniques.
Heavy Quark Effective Theory: The heavy quark effective theory is a framework used to describe the behavior of heavy quarks in quantum chromodynamics. It allows researchers to simplify the calculations involved in studying the behavior of these particles and to make predictions about their properties.
Jet Physics: Jet physics is the study of the collimated streams of particles that are produced in high-energy particle collisions. It is an important area of research in quantum chromodynamics, as it provides a way to test the predictions of the theory with experimental data.
Quantum Chromodynamics at High Temperatures: Quantum chromodynamics at high temperatures is a field of research that studies the behavior of matter at extremely high temperatures, such as those present in the early Universe shortly after the Big Bang. It is an important topic in quantum chromodynamics, as it provides insights into the behavior of matter under extreme conditions.
Composite Particles and Resonances: Composite particles and resonances are particles that are composed of other particles, such as mesons and baryons. Understanding the behavior of these particles is important in quantum chromodynamics, as they are the building blocks of hadrons.
Parton Distribution Functions: Parton distribution functions describe the probability of finding a parton inside a hadron with a certain momentum. They are used to make predictions about the behavior of particles in high-energy collisions.
Gluon Saturation: Gluon saturation is a phenomenon that occurs at high energies, where the density of gluons inside particles becomes so high that they begin to interact with each other in a non-linear way. It is an important topic in quantum chromodynamics, as it provides insights into the behavior of particles in extreme conditions.
Soft-Collinear Effective Theory: Soft-collinear effective theory is a framework used to describe the behavior of particles that have both soft and collinear momentum. It is an important tool in quantum chromodynamics, as it allows researchers to make predictions about the behavior of particles in high-energy collisions.
"Quarks are fundamental particles that make up composite hadrons such as the proton, neutron, and pion."
"QCD is a type of quantum field theory called a non-abelian gauge theory, with symmetry group SU(3)."
"Gluons are the force carriers of the theory, just as photons are for the electromagnetic force in quantum electrodynamics."
"The QCD analog of electric charge is a property called color."
"The theory is an important part of the Standard Model of particle physics."
"Color confinement is well established from lattice QCD calculations and decades of experiments."
"The asymptotic freedom of QCD was discovered in 1973 by David Gross and Frank Wilczek, and independently by David Politzer in the same year."
"Chiral symmetry breaking is the spontaneous symmetry breaking of an important global symmetry of quarks."
"Chiral symmetry breaking generates masses for hadrons far above the masses of the quarks, making pseudoscalar mesons exceptionally light."
"Yoichiro Nambu was awarded the 2008 Nobel Prize in Physics for elucidating the phenomenon [chiral symmetry breaking], a dozen years before the advent of QCD."
"A large body of experimental evidence for QCD has been gathered over the years."
"The energy grows until a quark–antiquark pair is spontaneously produced, turning the initial hadron into a pair of hadrons instead of isolating a color charge."
"There is a steady reduction in the strength of interactions between quarks and gluons as the energy scale of those interactions increases (and the corresponding length scale decreases)."
"Lattice simulations have confirmed all his [Yoichiro Nambu's] generic predictions."
"QCD is a type of quantum field theory called a non-abelian gauge theory, with symmetry group SU(3)."
"Quarks are fundamental particles that make up composite hadrons such as the proton, neutron, and pion."
"David Gross and Frank Wilczek, and independently David Politzer, all shared the 2004 Nobel Prize in Physics."
"Yoichiro Nambu elucidated the phenomenon of chiral symmetry breaking, which is a fundamental aspect of QCD."
"Color confinement is well established from lattice QCD calculations and decades of experiments, which show that the energy between two color charges remains constant as they are separated, ultimately leading to the creation of a quark-antiquark pair and the formation of hadrons."