pion(redirected from PIONA)
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Any of the three least massive mesons, having a positive, neutral, or negative electric charge. The charged pions have a mass 273 times that of an electron and a mean lifetime of 2.6 × 10-8 second, and the neutral pion has a mass 264 times that of an electron and a mean lifetime of 8.4 × 10-17 second. Also called pi meson.
[Contraction of pi meson.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(General Physics) 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
[C20: from Greek letter pi1 + on]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
any of the three lightest mesons, having positive, negative, or neutral electric charge and spin of zero.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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|Noun||1.||pion - a meson involved in holding the nucleus together; produced as the result of high-energy particle collision|
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