weak force

American  

noun

Physics.

1. a force between elementary particles that causes certain processes that take place with low probability, as radioactive beta-decay and collisions between neutrinos and other particles.

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weak force Scientific  

/ wēk /

1. The fundamental force that acts between leptons and is involved in the decay of hadrons. The weak nuclear force is responsible for nuclear beta decay (by changing the flavor of quarks) and for neutrino absorption and emission. It is mediated by the intermediate vector bosons (the W boson and the Z boson), and is weaker than the strong nuclear force and the electromagnetic force but stronger than gravity. Some scientists believe that the weak nuclear force and the electromagnetic force are both aspects of a single force called the electroweak force.

2. Also called weak nuclear force weak interaction

3. Compare electromagnetic force

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weak force Cultural  

1. One of the four fundamental forces of nature. It is involved primarily in the phenomenon of radioactivity. (See standard model and strong force.)

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Etymology

Origin of weak force

First recorded in 1965–70

Example Sentences

A deuteron contains just one proton and one neutron, held together by a relatively weak force.

From Science Daily • Dec. 27, 2025

Of the four fundamental forces, gravity and the weak force "are generally not important for materials," he says.

From Science Daily • Apr. 3, 2024

The electromagnetic force is conveyed by the photon, the strong force by the gluon, and the weak force by particles called the W boson and Z boson.

From Science Magazine • Mar. 27, 2024

The remaining two are more obscure: the strong force binds protons and neutrons together within atomic nuclei, whereas the weak force helps atoms and subatomic particles to fall apart via a form of radioactive decay.

From Scientific American • Aug. 19, 2023

It was also found that the weak force did not obey the symmetry C. That is, it would cause a universe composed of antiparticles to behave differently from our universe.

From "A Brief History of Time: And Other Essays" by Stephen Hawking