FACTOID # 26: Delaware is the latchkey kid capital of America, with 71.8% of households having both parents in the labor force.

 Home Encyclopedia Statistics States A-Z Flags Maps FAQ About

 WHAT'S NEW

SEARCH ALL

Search encyclopedia, statistics and forums:

(* = Graphable)

Encyclopedia > Weak nuclear force

The weak nuclear force or weak interaction is one of the four fundamental forces of nature. It is most commonly seen in beta decay and the associated radioactivity. The predicate weak derives from the fact that the field strength is some 1013 times less than that of the strong nuclear force. The term nuclear indicates that it is a short-range force, limited to distances smaller than an atomic nucleus. A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... A stylized representation of a lithium atom. ...

## Contents

The weak nuclear force affects all leptons and quarks. It is the only force affecting neutrinos (except for gravitation, which is negligible on laboratory scales). The weak interaction enables all lepton and quark particles and antiparticles to interchange energy, mass, electric charge and flavor—effectively to change into each other. In physics, a particle is a lepton if it has a spin of 1/2 and does not experience the strong nuclear force. ... For other uses of this term, see: Quark (disambiguation) 1974 discovery photograph of a possible charmed baryon, now identified as the Σc++ In particle physics, the quarks are subatomic particles thought to be elemental and indivisible. ... The neutrino is an elementary particle. ... Jump to: navigation, search Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interactions. ... In particle physics, flavor is a property of a fermion that identifies it, a label that specifies the name of the particle. ...

Although the weak nuclear force used to be described by Fermi's theory of a contact four-fermion interaction, today we know that it is mediated by the W and Z bosons. Because of their large mass of about 90 GeV/c2, their mean life is limited to about $3 times 10^{-25}$seconds by the uncertainty principle: In physics, Fermis interaction is an old explanation of the weak force, proposed by Enrico Fermi. ... Fermions, named after Enrico Fermi, are particles which form totally-antisymmetric composite quantum states. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Jump to: navigation, search In quantum physics, the Heisenberg uncertainty principle states that one cannot assign with full precision values for certain pairs of observable variables, including the position and momentum, of a single particle at the same time. ...

$Delta EcdotDelta tgeqhbar/2$

Even at the speed of light this effectively limits the range of the weak nuclear force to 10 − 18 meters, or about 1000 times smaller than the diameter of an atomic nucleus. A stylized representation of a lithium atom. ...

The Standard Model of particle physics describes the electromagnetic force and the weak nuclear force as two different aspects of a single electroweak force, the theory of which was developed around 1968 by Sheldon Glashow, Abdus Salam and Steven Weinberg (more at W and Z bosons). They were awarded the 1979 Nobel Prize in Physics for their work. The Standard Model of Fundamental Particles and Interactions The Standard Model of particle physics is a theory which describes the strong, weak, and electromagnetic fundamental forces, as well as the fundamental particles that make up all matter. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... In physics, the electroweak theory presents a unified description of two of the four fundamental forces of nature: electromagnetism and the weak nuclear force. ... Professor Sheldon Lee Glashow (born December 5, 1932) is an American physicist. ... Jump to: navigation, search Prof. ... Steven Weinberg at Harvard University Steven Weinberg (born May 3, 1933) is an American physicist. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... Jump to: navigation, search Hannes AlfvÃ©n, 1970 winner for work on astrophysical plasmas List of Nobel Prize laureates in Physics from 1901 to the present day. ...

## Decay via the weak force

A weak decay is the process of decomposing a heavier particle into lighter particles (plus energy) by the weak force.

A typical example is that of beta decay. In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ...

And to put thing on bottoms.

## References

• Griffiths, David J. (1987). Introduction to Elementary Particles, Wiley, John & Sons, Inc. ISBN 0471603864

David J. Griffiths is a U.S. physicist and educator. ...

Results from FactBites:

 force. The Columbia Encyclopedia, Sixth Edition. 2001-05 (548 words) Since mass is constant at ordinary velocities, the result of the force is a change in velocity, or an acceleration, which may be a change either in the speed or in the direction of the velocity. The strong nuclear force, or strong interaction, is associated with certain reactions between elementary particles and is responsible for holding the atomic nucleus together. The weak nuclear force, or weak interaction, is associated with beta particle emission and particle decay; it is weaker than the electromagnetic force but stronger than the gravitational force.
 fundamental force concept from the Astronomy knowledge base (839 words) One of the four fundamental forces of nature, it is carried by photons and is responsible for all observed macroscopic forces, except for gravity., One of the four fundamental forces of nature. The other three fundamental forces are the gravitational force, the weak nuclear force, and the strong nuclear force., One of the four fundamental forces of nature, governing the electric and magnetic interaction between particles., The phenomena associated with electrical and magnetic forces. strong force (11 facts) (nuclear force) - Strongest of the four fundamental forces, responsible for keeping quarks locked inside protons and neutrons and for keeping protons and neutrons crammed inside of atomic nuclei., The short-range nuclear force which is assumed to be responsible for binding the nucleus together.
More results at FactBites »

Share your thoughts, questions and commentary here