pion

[ pahy-on ]

/ ˈpaɪ ɒn /

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noun Physics.

the first meson to be discovered: it has spin 0 and may be positively or negatively charged or neutral; charged pions decay into a muon and a neutrino or antineutrino. Symbol: π

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Also called pi meson.

Origin of pion

First recorded in 1950–55; pi (meson) + -on¹

Words nearby pion

pinyon jay, Pinza, Pinzón, PIO, piolet, pion, pioneer, Pioneer Day, piopio, piosity, pious

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use pion in a sentence

Specifically, the proton morphs into a neutron and a pion made of one up quark and one down antiquark.
Decades-Long Quest Reveals Details of the Proton’s Inner Antimatter|Natalie Wolchover|February 24, 2021|Quanta Magazine
The pion saplings, which the dancers also pretended to swallow, had no deceptive arrangement.
The Mountain Chant, A Navajo Ceremony|Washington Matthews
In reality, each boy is an unpaid pion, a watchdog whose vigilance never relaxes.
The Secret Glory|Arthur Machen
Pion; A certaine great, round, and Bulbus-rooted flower, of one whole colour.
The plant-lore and garden-craft of Shakespeare|Henry Nicholson Ellacombe

Close at hand was a pion tree, which spread out low-growing branches all about.
The Motor Rangers Through the Sierras|Marvin West
Both the pion and the camass are largely utilized even at the present day for food by the Indians.
North America|Israel C. Russell

British Dictionary definitions for pion

pion

pi meson

/ (ˈpaɪɒn) /

noun

physics a meson having a positive or negative charge and a rest mass 273.13 times that of the electron, or no charge and a rest mass 264.14 times that of the electron

Word Origin for pion

C20: from Greek letter pi 1 + on

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for pion

pion

[ pī′ŏn′ ]

A meson occurring either in a neutral form with a mass 264 times that of an electron and a mean lifetime of 8.4 X 10-17 seconds or in a positively or negatively charged form with a mass 273 times that of an electron and a mean lifetime of 2.6 X 10-8 seconds. The pion was once believed to be the particle that mediates the strong force, which holds nucleons together in the nucleus; it is now believed that the gluon is the mediator particle. Pions do interact with nucleons, however, and are able to transform neutrons into protons and vice versa. Also called pi-meson See Table at subatomic particle.