weak force


Definition of weak force

: a fundamental physical force that governs interactions between hadrons and leptons (as in the emission and absorption of neutrinos) and is responsible for particle decay processes (such as beta decay) in radioactivity, that is 10-5 times the strength of the strong force, and that acts over distances smaller than those between nucleons in an atomic nucleus

called also weak interaction, weak nuclear force

— compare electromagnetism sense 2a, gravity sense 3a(2), strong force

Examples of weak force in a Sentence

Recent Examples on the Web Thus, weak force interactions will happen either more or less, depending on the electron’s spin. Don Lincoln, Forbes, 7 May 2021 That tiny asymmetry would signal the effect of the weak force, and its size would reveal the spatial spread of the neutrons. Adrian Cho, Science | AAAS, 27 Apr. 2021 Such a thin fiber is extremely compliant, so even a very weak force yields a relatively large rotation. Ben Brubaker, Scientific American, 10 Mar. 2021 The prizewinners studied weak-force interactions at high energies by creating a beam of neutrinos, which do not interact through the strong force but do so by the weak force. Washington Post, 17 Dec. 2020 This happens when the quarks exchange a particle called a W boson — one of the carriers of the weak force, with an electric charge of either +1 or −1. Quanta Magazine, 22 Oct. 2020 Pions slamming into the atmosphere produce showers of particles including electrons and their heavier siblings, muons, all of which are equipped by the weak force with the same chiral magnetic orientation relative to their path. Quanta Magazine, 29 June 2020 Finally, direct detection experiments like LZ and SuperCDMS hope that dark matter particles occasionally interact with normal matter via the weak force, allowing them to be spotted by extremely sensitive detectors. Emily Toomey, Smithsonian Magazine, 3 Feb. 2020 These particles convey one of the four fundamental forces, called the weak force, which causes radioactive decay. Quanta Magazine, 7 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'weak force.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of weak force

1968, in the meaning defined above

Keep scrolling for more

Learn More about weak force

Time Traveler for weak force

Time Traveler

The first known use of weak force was in 1968

See more words from the same year

Statistics for weak force

Last Updated

10 May 2021

Cite this Entry

“Weak force.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/weak%20force. Accessed 12 Jun. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More from Merriam-Webster on weak force

Britannica.com: Encyclopedia article about weak force


Test Your Vocabulary

Name that Thing: Dog Breeds

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!