psi particle

[ sahy, psahy ]
/ saɪ, psaɪ /
Save This Word!

noun Physics.
any of a family of mesons consisting of a charmed quark and a charmed antiquark.
an early name for the J/psi particle.
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?

Origin of psi particle

First recorded in 1970–75
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for psi particle

psi particle

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 psi particle (1 of 2)

psi′ particle
[ sīprīm, psī- ]

An electrically neutral meson having a mass 7,213 times that of the electron and a mean lifetime of approximately 1 X 10-20 seconds, composed, like the J/psi particle, of a charm-anticharm quark pair. See Table at subatomic particle.

Scientific definitions for psi particle (2 of 2)

psi particle
[ sī, psī ]

See J/psi particle.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.