Glossary
Electromagnetism
nonpermeable  same magnetic permeability as free space
grounded  potential fixed at zero
plasma frequency  resonant frequency of electron oscillations in a plasma
invariant mass 
relativistic mass  E/c^2
Quantum Mechanics
classical spins  can only be up or down
local potential  velocity independent (Abers' definition)
central potential  spherically symmetric
attractive potential  always less than value at infinity
singlet state  total spin is zero
triplet state  total spin is one
dipole transition  component of vector in the matrix element
cnumber  commutes like scalars (Shankar page 54)
qnumber  noncommuting like operators (Shankar page 54)
exchange force  apparent force due to Pauli exclusion
Thermodynamics
integrals of motion  constants of motion
diathermal  heat conductor
adiabatic  heat insulator
quasistatic  stays infinitesimally close to equilibrium
ideal gas  noninteracting particles
degenerate gas  obeys FD or BE statistics
thermodynamic equilibrium  mechanical, thermal, and chemical equilibrium
kinetic theory  detailed study of particle interactions
statistical weight  parameter of ln in conventional definition of entropy
occupancy  particlesperquantumstate function
dispersion relation  relation between energy and momentum
boltzmann factor  canonical weighting factor
equation of state
intensive parameter
extensive parameter
internal parameter
external parameter
microscopic parameter
macroscopic parameter
classical regime
Classical Mechanics
virial  a certain function relating to a system of forces and their points of application, first used by Clausius in the investigation of problems in molecular physics. Etymology: Latin expression vis, viris, force.
Source: Webster's Revised Unabridged Dictionary (1913).
elastic collision  collision in which kinetic energy is conserved
inelastic collision of the first kind (endoergic collision)  collision in which kinetic energy is lost
inelastic collision of the second kind (superelastic collision, exoergic collision)  collision in which kinetic energy is gained
Particle Physics
scalar particle  particle of spin zero
vector particle  particle of nonzero spin
fermion  a particle with half integer spin
boson  a particle with integer spin
gauge boson  a boson that acts as a mediator of a fundamental interaction
Majorana fermion  a fermion that is its own antiparticle
Dirac fermion  a fermion that is not its own antiparticle
valence quark  a quark which imparts quantum numbers onto a hadron
sea quark  a virtual quark in a hadron that does not contribute to the hadron's quantum number
lepton universality  the couplings of the leptons to gauge bosons are flavorindependent
Mathematics
power law  variable to a constant power
