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

The axion is distinctly different from another lightweight, weakly-interacting particle, the neutrino, which only interacts through gravity and the weak force and totally ignores the electromagnetic force.

From Science Daily • Nov. 21, 2024

In the standard model, simply plugging in the W and Z masses ruins the mathematical symmetry that produces the weak force in the first place.

From Science Magazine • Mar. 27, 2024

Instead of an electromagnetic interaction, neutrinos interact via a different force called the weak force.

From Scientific American • Mar. 16, 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