Beauty and Charm Glossary

This glossary is provided for teacher reference only and is not intended for direct teaching or memorization.

Accelerator - A machine that serves as a source for a well-defined beam of high speed particles for studies in nuclear science and high energy (or particle) physics.

Antiparticle - Particle with the same mass but opposite charge (and some other properties) as another particle under normal earth conditions.

Atom - The basic structural unit of each of the elements in the Periodic Table. Atoms are composed of protons, neutrons and electrons.

Bohr Model - Model of the atom proposed by Neils Bohr in 1913. It showed electrons in fixed orbits around the nucleus, but acting in some ways like waves.

Bubble Chamber - A container filled with a liquid under low pressure so that a moving, charged particle initiates "boiling" in the liquid along its path. This track of bubbles is recorded on stereophotographs.

Circular Accelerator - Scientific machine in which particles are accelerated as they travel around a circular path.

Electromagnetic Force - Attraction or repulsion due to the electric charge of matter.

Electron - A point-like particle with a negative charge; member of the lepton group and thus not divisible into more fundamental particles.

Electron Cloud Model - Current model of the atom in which electrons are located in regions according to rules of probability rather than in defined orbits.

Electron Volt (eV) - The amount of energy given to an electron when passing from the negative end to the positive end of a one-volt battery.

Gluon - Carrier of the strong force which binds quarks together in protons, neutrons, and other particles.

Graviton - A massless particle whose exchange between masses is thought to produce the gravitational force.

Gravity - The attraction of mass to all other mass. Gravity is the weakest known force in nature at normal energies.

Hadron - Particles made up of two or three quarks bound together by the strong force.

Lepton - An indivisible fundamental particle. There are six leptons plus their antiparticles.

Linear Accelerator - Also called a Linac, a scientific machine in which particles are accelerated in groups along a straight line path.

Macrocosm - A large system.

Microcosm - A very small system, such as an atom.

Neutrino - A lepton of zero mass and zero electric charge.

Neutron - A particle with mass slightly larger than that of the proton, but with zero electric charge; a neutron is a hadron and is made up of three quarks.

Nucleus - Positively charged central core of an atom which is responsible for almost the entire mass of the atom. It is made up of protons and neutrons.

Photon - A particle with zero rest mass that transmits the electromagnetic force. Light is made up of photons whose energy depends on the wavelength of light.

Proton - A positively charged particle 2,000 times more massive than an electron that, with neutrons, forms all nuclear matter; a proton is a hadron and is made up of three quarks.

Quark - A fundamental particle. There are six quarks (but only five have been observed) plus their antiquarks. Each quark and antiquark exists in three "colors."

Strong Force - Force that binds quarks and holds the nucleus of an atom together. It is the strongest force in nature.

Superconductor - A metal that when cooled below a critical temperature has a total disappearance of electrical resistance. Twenty-five elements and many alloys and compounds have been found to be superconducting. The critical temperatures range from .002 k to 18K (-273 C to -255 C).

Unified Field Theory - The single physical principle or law that would explain the link between the four known forces of nature.

Weak Force - The interaction that controls radioactive decay.

KeV - thousand electron volts (103)

GeV - billion electron volts (109)

MeV - million electron volts (106)

TeV - trillion electron volts (1012)