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

See Examples For:

weak force

The four fundamental forces – gravity, electromagnetism, the weak force and the strong force – govern how these particles interact.

From Science Daily ● May 26, 2026

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

From Science Daily ● Dec. 27, 2025

The electromagnetic force is long range because the photon has no mass, and the weak force is short range because the particles that convey it, the W and Z, are massive.

From Science Magazine ● Mar. 27, 2024

When scientists access such “young cosmos” states with particle accelerators, they see electromagnetism and the weak force acting as one single force—the electroweak force—suggesting that in the early universe, these two forces were one.

From Scientific American ● Aug. 19, 2023

The weak force engages in more miscellaneous tasks, mostly to do with controlling the rates of certain sorts of radioactive decay.

From "A Short History of Nearly Everything" by Bill Bryson