any of a family of mesons consisting of a charmed quark and a charmed antiquark.
an early name for the J/psi particle.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
British Dictionary definitions for psi particle
See J/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)
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)
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.