Astrophysics (index) | about |

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 integer or 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*.

http://en.wikipedia.org/wiki/Boson

http://en.wikipedia.org/wiki/Lepton

http://en.wikipedia.org/wiki/Hadron

http://en.wikipedia.org/wiki/List_of_particles

absorption

absorption coefficient

Advanced Composition Explorer (ACE)

advection dominated accretion flow (ADAF)

alpha particle

antimatter

ARCADE

atmospheric escape

axion (A

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

Cherenkov radiation

CNO cycle

coherent light

collimator

column density

Compton scattering

cooling function

cosmic rays (CR)

cross section

curvature radiation

cyclotron radiation

dark matter (DM)

dark matter annihilation

de Broglie wavelength

degeneracy weight

diffraction

diffusion

Doppler broadening

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

radiation pressure

radioactive decay

Rayleigh scattering

relativistic speed

solar energetic particle (SEP)

superluminous supernova (SLSN)

Solar and Heliospheric Observatory (SOHO)

solar storm

solar wind

spectrometer

spectrometry

spin (m

synchrotron self-Compton (SSC)

standard model

standard model of a flare

stellar structure

STEREO

Stokes number (Stk)

supersymmetry

synchrotron radiation

temperature

thermodynamic equilibrium (TE)

Thomson scattering

Van Allen belts

VHE

Voyager

wave-particle duality

white dwarf

WIMP