Glossary
Particle Adventure glossary
80 definitions · page 2 of 2.
- Residual Interaction
- An interaction between objects that do not carry a charge but do contain constituents that have that charge. Although some chemical substances involve electrically-charged ions, much of chemistry is due to residual electromagnetic interactions between…
- Rest Mass
- The rest mass (m) of a particle is the mass defined by the energy of the isolated (free) particle at rest, divided by the speed of light squared. When particle physicists use the word "mass," they always mean the "rest mass" (m) of the object in question.
- SLAC
- The Stanford Linear Accelerator Center in Stanford, California.
- Spin
- A quantum particle property of intrinsic angular momentum.
- Stable
- Does not decay. A particle is stable if there exist no processes in which a particle disappears and in its place different particles appear.
- Standard Model
- Physicists have developed a theory of fundamental particles and interactions called the Standard Model. This site describes various aspects of this model.
- Strange Quark (s)
- The third flavor of quark (in order of increasing mass), with electric charge -1/3.
- Strong Interaction
- The interaction responsible for binding quarks, antiquarks, and gluons to make hadrons. Residual strong interactions provide the nuclear binding force.
- Subatomic Particle
- Any particle that is small compared to the size of the atom.
- Synchrotron
- A type of circular accelerator in which the particles travel in synchronized bunches at fixed radius.
- Tau (t)
- The third flavor of charged lepton (in order of increasing mass), with electric charge -1.
- Top Quark (t)
- The sixth flavor of quark (in order of increasing mass), with electric charge 2/3. Its mass is much greater than any other quark or lepton.
- Track
- The record of the path of a particle traversing a detector.
- Tracking
- The reconstruction of a "track" left in a detector by the passage of a particle through the detector.
- Uncertainty Principle
- The quantum principle, first formulated by Heisenberg, that states that is is not possible to know exactly both the position x and the momentum p of an object at the same time. The same is true with energy and time (see virtual particle).
- Up Quark
- The least massive flavor of quark, with electric charge 2/3.
- Virtual Particle
- A particle that exists only for an extremely brief instant in an intermediary process. Then the Heisenberg Uncertainty Principle allows an apparent violation of the conservation of energy. However, if one sees only the initial decaying particle and the final…
- W+ W- Boson
- A carrier particle of the weak interactions. It is involved in all electric-charge-changing weak processes.
- Weak Interaction
- The interaction responsible for all processes in which flavor changes, hence for the instability of heavy quarks and leptons, and particles that contain them. Weak interactions that do not change flavor (or charge) have also been observed.
- Z Boson
- A carrier particle of the weak interactions. It is involved in all weak processes that do not change flavor