Citizendia
Your Ad Here

In particle physics, fermions are particles with a half-integer spin, such as protons and electrons. Particle physics is a branch of Physics that studies the elementary constituents of Matter and Radiation, and the interactions between them In Mathematics, a half-integer is a Number of the form n + 1/2 where n is an Integer. In Quantum mechanics, spin is a fundamental property of atomic nuclei, Hadrons and Elementary particles For particles with non-zero spin The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J They obey the Fermi-Dirac statistics and are named after Enrico Fermi. In Statistical mechanics, Fermi-Dirac statistics is a particular case of Particle statistics developed by Enrico Fermi and Paul Dirac that In the Standard Model there are two types of elementary fermions: quarks and leptons. The Standard Model of Particle physics is a theory that describes three of the four known Fundamental interactions together with the Elementary particles In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made In Physics, a quark (kwɔrk kwɑːk or kwɑːrk is a type of Subatomic particle. Leptons are a family of fundamental Subatomic particles comprising the Electron, the Muon, and the Tauon (or tau particle as well as their The 24 fundamental fermionic flavours are:

In contrast to bosons, only one fermion can occupy a quantum state at a given time (they obey the Pauli Exclusion Principle). In Particle physics, bosons are particles which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein In Quantum physics, a quantum state is a mathematical object that fully describes a quantum system. The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925 Thus, if more than one fermion occupies the same place in space, the properties of each fermion (e. g. its spin) must be different from the rest. Therefore fermions are usually related with matter while bosons are related with radiation, though the separation between the two is not clear in quantum physics. Matter is commonly defined as being anything that has mass and that takes up space. In Particle physics, bosons are particles which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein Radiation, as in Physics, is Energy in the form of waves or moving Subatomic particles emitted by an atom or other body as it changes from a higher energy

Contents

Basic properties

Due to their half-integer spin, as an observer circles a fermion (or as the fermion rotates 360° about its axis) the wavefunction of the fermion changes sign. A wave function or wavefunction is a mathematical tool used in Quantum mechanics to describe any physical system A related phenomenon is called an antisymmetric wavefunction behavior of a fermion. Fermions obey Fermi-Dirac statistics, meaning that when one swaps two fermions, the wavefunction of the system changes sign. In Statistical mechanics, Fermi-Dirac statistics is a particular case of Particle statistics developed by Enrico Fermi and Paul Dirac that A wave function or wavefunction is a mathematical tool used in Quantum mechanics to describe any physical system A consequence of this is the Pauli exclusion principle — no two fermions can occupy the same quantum state at the same time. The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925 In Quantum physics, a quantum state is a mathematical object that fully describes a quantum system. This results in "rigidness" or "stiffness" of matter which include fermions (atomic nuclei, atoms, molecules, etc), so fermions are sometimes said to be the constituents of matter, and bosons to be particles that transmit interactions (forces), or constituents of radiation. Matter is commonly defined as being anything that has mass and that takes up space. In Particle physics, bosons are particles which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein In Physics, a force is whatever can cause an object with Mass to Accelerate. Radiation, as in Physics, is Energy in the form of waves or moving Subatomic particles emitted by an atom or other body as it changes from a higher energy

The Pauli exclusion principle obeyed by fermions is responsible for the "rigidness" of ordinary matter (it is a major contributor to Young modulus), and for the stability of the electron shells of atoms (thus for stability of atomic matter). The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925 In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other It also is responsible for the complexity of atoms (making it impossible for all atomic electrons to occupy the same energy level), thus making complex chemistry possible. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties It is also responsible for the pressure within degenerate matter which largely governs the equilibrium state of white dwarfs and neutron stars. Degenerate matter is matter which has sufficiently high Density that the dominant contribution to its Pressure rises from the Pauli Exclusion A white dwarf, also called a degenerate dwarf, is a small Star composed mostly of Electron-degenerate matter. A neutron star is a type of remnant that can result from the Gravitational collapse of a massive Star during a Type II, Type Ib or Type

In large systems, the difference between bosonic and fermionic statistics is only apparent at large densities when their wave functions overlap. At low densities, both types of statistics are well approximated by Maxwell-Boltzmann statistics, which is described by classical mechanics. In Statistical mechanics, Maxwell–Boltzmann statistics describes the statistical distribution of material particles over various energy states in Thermal equilibrium Classical mechanics is used for describing the motion of Macroscopic objects from Projectiles to parts of Machinery, as well as Astronomical objects

Elementary fermions

All observed elementary particles are either fermions or bosons. In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made In Particle physics, bosons are particles which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein The known elementary fermions are divided into two groups: quarks and leptons. In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made In Physics, a quark (kwɔrk kwɑːk or kwɑːrk is a type of Subatomic particle. Leptons are a family of fundamental Subatomic particles comprising the Electron, the Muon, and the Tauon (or tau particle as well as their

The quarks make up protons and neutrons, which are composite fermions. In Physics, a quark (kwɔrk kwɑːk or kwɑːrk is a type of Subatomic particle. The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron.

Leptons include the electron and similar, heavier particles (muon and tauon) and neutrino. Leptons are a family of fundamental Subatomic particles comprising the Electron, the Muon, and the Tauon (or tau particle as well as their The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The muon (from the letter mu (μ--used to represent it is an Elementary particle with negative Electric charge and a spin of 1/2 The tau lepton (often called the tau, tau particle, or occasionally the tauon; symbol) is a negatively charged Elementary particle with Neutrinos are Elementary particles that travel close to the Speed of light, lack an Electric charge, are able to pass through ordinary matter almost

The known fermions of left-handed helicity interact through the weak interaction while the known right-handed fermions do not. In Particle physics, helicity is the projection of the spin \vec S onto the direction of momentum \hat p: h = \vec The weak interaction (often called the weak force or sometimes the weak nuclear force) is one of the four Fundamental interactions of nature Or put another way, only left-handed fermions and right-handed anti-fermions couple to the W boson. The W and Z bosons are the Elementary particles that mediate the Weak force.

Composite fermions

In addition to elementary fermions and bosons, nonrelativistic composite particles made up of more fundamental particles bound together through a potential energy are fermions or bosons, depending only on the number of fermions they contain:

The number of bosons within a composite particle made up of simple particles bound with a potential has no effect on whether it is a boson or a fermion.

In a quantum field theory, the situation is more interesting. In quantum field theory (QFT the forces between particles are mediated by other particles There can be field configurations of bosons which are topologically twisted. These are coherent states which behave like a particle, and they can be fermionic even if all the elementary particles are bosons. This was discovered by Tony Skyrme in the early 1960s, so fermions made of bosons are named Skyrmions after him. Tony Hilton Royle Skyrme, (1922-1987 was a British physicist. In Theoretical physics, a skyrmion, conceived by Tony Skyrme, is a mathematical model used to model Baryons (a Subatomic particle)

Skyrme's original example involves fields which take values on a three dimensional sphere, the original nonlinear sigma model that describes the large distance behavior of pions. In Quantum field theory, a nonlinear &sigma model describes a Scalar field &Sigma which takes on values in a nonlinear manifold called the Target manifold In Particle physics, pion (short for pi meson) is the collective name for three Subatomic particles, and. In Skyrme's model, which is reproduced in the large N or string approximation to QCD, the proton and neutron are fermionic topological solitons of the pion field. In Theoretical physics, the AdS/QCD correspondence is a program to describe Quantum Chromodynamics (QCD in terms of a dual gravitational theory following the principles Also see base concepts Topology, Differential equations Quantum theory & Condensed matter physics. While Skyrme's example involves pion physics, there is a much more familiar example in quantum electrodynamics with a magnetic monopole. In Physics, a magnetic monopole is a hypothetical particle that is a Magnet with only one pole (see Maxwell's equations for more on magnetic A bosonic monopole with the smallest possible magnetic charge and a bosonic version of the electron would form a fermionic dyon. In Physics, a magnetic monopole is a hypothetical particle that is a Magnet with only one pole (see Maxwell's equations for more on magnetic In Physics, a dyon is a hypothetical particle with both electric and magnetic charges

Fermionic or bosonic behavior of a composite particle (or system) is only seen at large (compared to size of the system) distance. At proximity, where spatial structure begins to be important, a composite particle (or system) behaves according to its constituent makeup. For example, two atoms of helium can not share the same space if it is comparable by size to the size of the inner structure of the helium atom itself (~10−10 m)—despite bosonic properties of the helium atoms. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Thus, liquid helium has finite density comparable to the density of ordinary liquid matter. Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of

See also

This is a list of the different types of particles known and hypothesized In Quantum field theory, a fermionic field is a Quantum field whose quanta are Fermions that is they obey Fermi-Dirac statistics. Identical particles, or indistinguishable particles, are particles that cannot be distinguished from one another even in principle In Quantum mechanics and Statistical mechanics, parastatistics is one of several alternatives to the better known Particle statistics models (

Dictionary

fermion

-noun

  1. (physics) A particle with totally antisymmetric composite quantum states, which means they must obey the Pauli exclusion principle, and that obey Fermi-Dirac statistics. They have half-integer spin. Among them are many elementary particles, most derived from quarks. Compare boson.
© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic