Also found in: Encyclopedia, Wikipedia.


n. Abbr. I
A quantum number related to the number of charge states of a baryon or meson.

[iso(topic) + spin.]
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) an internal quantum number used in the classification of elementary particles. Particles which have very similar properties except for those associated with their charge are regarded as forms of the same fundamental particle with different components of the isospin in a certain direction in an imaginary space. Also called: isobaric spin or isotopic spin
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

i′sotop′ic spin′

a quantum number that is related to the number of different values of electric charge that a given kind of baryon or meson may have. Symbol: I Also called isospin.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
We also take into account the effect of isospin mixing between I = 0 and I = 1, as well as possible [SIGMA] (1385) contamination in the observed spectrum.
In the concept of isospin, proton and neutron are viewed as two states of the same quantum oscillator.
By considering the isospin symmetric modes of the measured channels, we can estimate the lower limits on the leptonic partial width of the Y(4220) and Y(4390) decays.
Puri, "Elliptical flow and isospin effects in heavy-ion collisions at intermediate energies," Physical Review C, vol.
Among the topics are no-core shell model and reactions, direct reactions with exotic nuclei, isoscaling and symmetry energy in dynamical fragment formation, "pasta" phases in dense stars, and isospin effects on fragmentation mechanisms.
In the case of the strong interaction, the gauge symmetry is the isospin symmetry--the strong interactions are invariant under rotations in the isospin space).
[G.sub.V] may be determined from the measured ft-values of the pure Fermi [0.sup.+] - [0.sub.+] superallowed [beta]-transitions within isospin triplets provided the relevant nuclear physics corrections may be applied with confidence [5].
Por ejemplo, en la interaccion fuerte entre neutrones y protones se conservan, aparte de la paridad, magnitudes tales como la masa llamada barionica (numero total de protones y neutrones), el isospin y la hipercarga, que no se conservan en la interaccion electrodebil.
Johnson orders his story around the progression of theories and discoveries in quantum thinking, providing an extraordinary wealth of detail on such recondite topics as particle parity, mathematical renormalization, isospin, and quantum chromodynamics.