particle

(very small thing)

Some particle-physics terms and associated characteristics:

 Particle term Spin Statistics Comment Examples fermion half-integer(1/2, 3/2, 5/2, ...) Fermi-Dirac Obeys Pauli exclusion principle leptons, quarks, baryons boson integer(0, 1, 2, ...) Bose-Einstein Some are elementary particles,others composite photon, gluon, W boson, Higgs bosonor a meson (a composite boson) lepton 1/2 Fermi-Dirac Elementary particle electron, muon, neutrino quark 1/2 Fermi-Dirac Elementary particle,Subject to strong force up, down, top, bottom, strange, charm hadron either integeror half-integer depends A composite particle,can be a fermion or boson any baryon, any meson baryon 1/2 Fermi-Dirac A composite particle made of three quarks,A type of hadron and a type of fermion protons, neutrons meson 0 or 1 Bose-Einstein A composite particle made up of a quark and antiquark,A type of hadron and a type of boson,Unstable: decays in a fraction of a second Pion, Many other types
• spin - a quantum number indicating a type of quantum angular momentum.
• Pauli exclusion principle - a characteristic of some particles (i.e., those with half-integer spin) that two such particles are never in close association if all their quantum numbers are identical: an example is all the electrons within an atom.
• Fermi-Dirac statistics - a statistical distribution of energy levels of particles when they are in thermodynamic equilibrium if the particles are ruled by the Pauli exclusion principle (as opposed to Bose-Einstein statistics).
• quantum number - quantum mechanical values associated with a particle or system of particles: the set of them varies by system: they are conserved, i.e., changes to the particles don't change the total sums of any of the numbers. Electric charge and spin are examples. Net electric charge, for example, does not change in a particle interaction.
• strong force - one of the fundamental forces: the force that holds protons, neutrons, and atomic nuclei together.

Atomic nuclei, ions, and (neutral) atoms all fall under the category of hadron (composite particle) and can be either a fermion or boson, depending upon the constituents.

Antimatter offers another dimension: some elementary particles have an associated antiparticle, e.g., a positron is an anti-electron, but both these two are leptons and fermions.

(physics,particles)
http://en.wikipedia.org/wiki/Fermion
http://en.wikipedia.org/wiki/Boson
http://en.wikipedia.org/wiki/Lepton
http://en.wikipedia.org/wiki/List_of_particles

Referenced by:
absorption
absorption coefficient
Advanced Composition Explorer (ACE)
alpha particle
antimatter
atmospheric escape
axion (A0)
baryon
beta decay
black hole (BH)
Blandford-Znajek mechanism (BZ process)
Boltzmann constant (k)
Boltzmann equation
Bose-Einstein statistics
bremsstrahlung
Cassini
cold dark matter (CDM)
Cherenkov detector
CNO cycle
coherent light
collimator
column density
Compton scattering
cooling function
cosmic rays (CR)
cross section
dark matter (DM)
dark matter annihilation
de Broglie wavelength
degeneracy weight
diffraction
diffusion
electron orbital
electron scattering
electron screening
electroweak
endothermic reaction
exosphere
Fokker-Planck equation
fusion
geodesic
GZK limit
Hamiltonian
heliosphere
interplanetary medium (IPM)
Jeans escape
Jeans parameter (λ)
JUICE
Juno
kinetic energy (KE)
line shape function
Lorentz force
MACHO
magnetosphere
Maxwell-Boltzmann distribution
Maxwell's equations
mean free path
neutralino
neutrino (ν)
neutron scattering
New Horizons (NF1)
nitrogen (N)
pair production
particle horizon
particle spectrometer
partition function (Z)
Pauli exclusion principle
photon
pion (π)
plasma
plasma frequency
pressure integral
quantum
quantum mechanics (QM)
quantum mixing
quantum number
quantum tunneling
Rayleigh scattering
relativistic speed
solar energetic particle (SEP)
superluminous supernova (SLSN)
Solar and Heliospheric Observatory (SOHO)
solar storm
solar wind
spectrometer
spectrometry
spin (ms)
synchrotron self-Compton (SSC)
standard model
standard model of a flare
stellar structure
STEREO
Stokes number (Stk)
supersymmetry