- baryon number
- a conserved physical quantity that is zero for mesons and leptons and for baryons and antibaryons, respectively
- baryons
- hadrons that always decay to another baryon
- boson
- particle with zero or an integer value of intrinsic spin
- bottom
- a quark flavor
- charm
- a quark flavor, which is the counterpart of the strange quark
- colliding beams
- head-on collisions between particles moving in opposite directions
- color
- a quark flavor
- conservation of total baryon number
- a general rule based on the observation that the total number of nucleons was always conserved in nuclear reactions and decays
- conservation of total electron family number
- a general rule stating that the total electron family number stays the same through an interaction
- conservation of total muon family number
- a general rule stating that the total muon family number stays the same through an interaction
- cyclotron
- accelerator that uses fixed-frequency alternating electric fields and fixed magnets to accelerate particles in a circular spiral path
- down
- the second-lightest of all quarks
- electron family number
- the number that is assigned to all members of the electron family, or the number 0 that is assigned to all particles not in the electron family
- electroweak theory
- theory showing connections between EM and weak forces
- fermion
- particle with a half-integer value of intrinsic spin
- Feynman diagram
- a graph of time versus position that describes the exchange of virtual particles between subatomic particles
- flavors
- quark type
- fundamental particle
- particle with no substructure
- gauge boson
- particle that carries one of the four forces
- gluons
- eight proposed particles which carry the strong force
- gluons
- exchange particles, analogous to the exchange of photons that gives rise to the electromagnetic force between two charged particles
- grand unified theory
- theory that shows unification of the strong and electroweak forces
- hadrons
- particles that feel the strong nuclear force
- Higgs boson
- a massive particle that, if observed, would give validity to the theory that carrier particles are identical under certain circumstances
- leptons
- particles that do not feel the strong nuclear force
- linear accelerator
- accelerator that accelerates particles in a straight line
- meson
- hadrons that can decay to leptons and leave no hadrons
- meson
- particle whose mass is intermediate between the electron and nucleon masses
- muon family number
- the number that is assigned to all members of the muon family, or the number 0 that is assigned to all particles not in the muon family
- particle physics
- the study of and the quest for those truly fundamental particles having no substructure
- pion
- particle exchanged between nucleons, transmitting the force between them
- quantum chromodynamics
- quark theory including color
- quantum chromodynamics
- the governing theory of connecting quantum number color to gluons
- quantum electrodynamics
- the theory of electromagnetism on the particle scale
- quark
- an elementary particle and a fundamental constituent of matter
- standard model
- combination of quantum chromodynamics and electroweak theory
- strange
- the third lightest of all quarks
- strangeness
- a physical quantity assigned to various particles based on decay systematics
- superstring theory
- a theory of everything based on vibrating strings some in length
- synchrotron
- a version of a cyclotron in which the frequency of the alternating voltage and the magnetic field strength are increased as the beam particles are accelerated
- synchrotron radiation
- radiation caused by a magnetic field accelerating a charged particle perpendicular to its velocity
- tau family number
- the number that is assigned to all members of the tau family, or the number 0 that is assigned to all particles not in the tau family
- theory of quark confinement
- explains how quarks can exist and yet never be isolated or directly observed
- top
- a quark flavor
- up
- the lightest of all quarks
- Van de Graaff
- early accelerator: simple, large-scale version of the electron gun
- virtual particles
- particles which cannot be directly observed but their effects can be directly observed