Strong interaction

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"The strong interaction is observable in two areas: on a larger scale (about 1 to 3 femtometers (fm)), it is the force that binds protons and neutrons (nucleons) together to form the nucleus of an atom. On the smaller scale (less than about 0.8 fm, the radius of a nucleon), it is also the force ... that [forms and holds together] protons, neutrons and other hadron particles."

Development status: this resource is experimental in nature.

"In the context of binding protons and neutrons together to form atoms, the strong interaction is called the nuclear force (or residual strong force). [T]he strong interaction ... obeys a quite different distance-dependent behavior between nucleons ... ."

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Resource type: this resource is an article.

Resource type: this resource contains a lecture or lecture notes.

Subject classification: this is a physics resource .

Notation

Notation: let the symbol Def. indicate that a definition is following.

Notation: let the symbols between [ and ] be replacement for that portion of a quoted text.

Universals

To help with definitions, their meanings and intents, there is the learning resource theory of definition.

Def. evidence that demonstrates that a concept is possible is called proof of concept.

The proof-of-concept structure consists of

1. background,
2. procedures,
3. findings, and
4. interpretation.

The findings demonstrate a statistically systematic change from the status quo or the control group.

History

"Before the 1970s ... it was known that the nucleus was composed of protons and neutrons and that the protons possessed positive electric charge while neutrons were electrically neutral."

"A stronger attractive force was postulated to explain how the atomic nucleus was bound together despite the protons' mutual electromagnetic repulsion. This hypothesized force was called the strong force, which was believed to be a fundamental force that acted on the nucleons (the protons and neutrons that make up the nucleus). Experiments suggested that this force bound protons and neutrons together with equal strength."

Behavior of the strong force

"Unlike [the] electromagnetic [and] weak [interactions], the strong force does not diminish in strength with increasing distance. After a limiting distance (about the size of a hadron) has been reached, it remains at a strength of about 10,000 newtons, no matter how much farther the distance between [hadrons]. The ... force between [hadrons] remains constant at any distance after [the hadrons] travel only a tiny distance from each other, and is equal to that need to raise one ton, which is 1000 kg x 9.8 N = ~ 10,000 N."

"[T]he amount of work done against a force of 10,000 newtons (about the weight of a one-metric ton mass on the surface of the Earth) is enough to create particle-antiparticle pairs within a very short distance of an interaction."

"The strong force is ... nearly absent between such hadrons (i.e., between baryons or mesons). In this case, only a residual force (described below) called the residual strong force acts between [these] hadrons, and this residual force diminishes rapidly with distance, and is thus very short-range (effectively a few femtometers)."

Residual strong force

"The residual effect of the strong force is called the nuclear force. The nuclear force acts between hadrons, such as mesons or the nucleons in atomic nuclei. This "residual strong force", acting indirectly, transmits ... pi and rho mesons, which, in turn, transmit the nuclear force between nucleons."

"The residual strong force is thus a minor residuum of the strong force which binds ... together ... protons and neutrons. This same force is much weaker between neutrons and protons, because it is mostly neutralized within them, in the same way that electromagnetic forces between neutral atoms (van der Waals forces) are much weaker than the electromagnetic forces that hold the atoms internally together. Unlike the strong force itself, the nuclear force, or residual strong force, does diminish in strength, and in fact diminishes rapidly with distance. The decrease is approximately as a negative exponential power of distance, though there is no simple expression known for this; see Yukawa potential. This fact, together with the less-rapid decrease of the disruptive electromagnetic force between protons with distance, causes the instability of larger atomic nuclei, such as all those with atomic numbers larger than 82 (the element lead)."

See also

• Coronal cloud
• Electroweak interaction
• Particle physics
• Stellar surface fusion
• Weak interaction

Further reading

• D.J. Griffiths (1987). Introduction to Elementary Particles. John Wiley & Sons. ISBN 0-471-60386-4. 
• F. Halzen, A.D. Martin (1984). Quarks and Leptons: An Introductory Course in Modern Particle Physics. John Wiley & Sons. ISBN 0-471-88741-2. 
• G.L. Kane (1987). Modern Elementary Particle Physics. Perseus Books. ISBN 0-201-11749-5. 
• R. Morris (2003). The Last Sorcerers: The Path from Alchemy to the Periodic Table. Joseph Henry Press. ISBN 0-309-50593-3. 

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