positron

noun

pos·​i·​tron ˈpä-zə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also antielectron

Examples of positron in a Sentence

Recent Examples on the Web The most common forms occur when an unstable nucleus spits out an alpha particle, consisting of two neutrons and two protons, a beta particle consisting of an energetic positron or electron, or a gamma ray, consisting of a high energy photon. The Physics Arxiv Blog, Discover Magazine, 27 Feb. 2024 Still odd, but not sterile STEREO detects neutrinos by their ability to transform a proton into a neutron, a process that results in the release of a positron, which can be detected. John Timmer, Ars Technica, 11 Jan. 2023 Beams of energy collide with atoms in Earth’s upper atmosphere, spawning charged subatomic particles like pions, muons, electrons, and positrons, whose ionized trails show up as spindly lines in cloud chambers. Bill Gourgey, Popular Science, 23 Nov. 2023 Two years later Carl Anderson, of the California Institute of Technology, detected positrons in cosmic ray showers, a discovery that earned him a Nobel Prize in Physics. Dennis Overbye, New York Times, 27 Sep. 2023 As early as the 1960s, physicists first thought about measuring gravity’s effects on positrons, or anti-electrons, which have positive rather than negative electric charge. Rahul Rao, Popular Science, 27 Sep. 2023 One was a study using positron emission tomography — PET scans — that showed different areas of the brain were associated with each form of memory. Michael S. Rosenwald, Washington Post, 3 Oct. 2023 The positron discovered by Paul Dirac had a mass and spin identical to that of an electron but an opposite electrical charge, not an opposite spin and charge. New York Times, 2 Oct. 2023 The imaging revolution, starting with the invention of the positron emission tomography (PET) scanner and the MRI in the 1970s, seemed to bring neuroscience out of the dark ages. Kristen Martin, Washington Post, 2 Aug. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'positron.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

positive + -tron (as in electron)

First Known Use

1933, in the meaning defined above

Time Traveler
The first known use of positron was in 1933

Dictionary Entries Near positron

Cite this Entry

“Positron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/positron. Accessed 19 Mar. 2024.

Kids Definition

positron

noun
pos·​i·​tron ˈpäz-ə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and size of charge as the electron

Medical Definition

positron

noun
pos·​i·​tron ˈpäz-ə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also positive electron

More from Merriam-Webster on positron

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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