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Related to Hadrons: antiquark, Mesons, Baryons


The generic name of a class of particles which interact strongly with one another. Examples of hadrons are protons, neutrons, the &pgr;, K, and D mesons, and their antiparticles. Protons and neutrons, which are the constituents of ordinary nuclei, are members of a hadronic subclass called baryons, as are strange and charmed baryons. Baryons have half-integral spin, obey Fermi-Dirac statistics, and are known as fermions. Mesons, the other subclass of hadrons, have zero or integral spin, obey Bose-Einstein statistics, and are known as bosons. The electric charges of baryons and mesons are either zero or ±1 times the charge on the electron. Masses of the known mesons and baryons cover a wide range, extending from the pi meson, with a mass approximately one-seventh that of the proton, to values of the order of 10 times the proton mass. The spectrum of meson and baryon masses is not understood. See Baryon, Bose-Einstein statistics, Fermi-Dirac statistics, Meson, Neutron, Proton

Based on an enormous body of data, hadrons are now thought to consist of elementary fermion constituents known as quarks which have electric charges of + |e| and |e|, where |e| is the absolute value of the electron charge. For example, a quark-antiquark pair makes up a meson, while three quarks constitute a baryon. See Elementary particle, Quarks

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.


(had -ron) See elementary particles. See also Big Bang theory.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006


(particle physics)
An elementary particle which has strong interactions.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
With regards to quarks, Sakata has considered in 1956 three basic hadrons (proton, neutron, and alphaparticle) and three basic leptons (electron, muon, neutrino).
"So that's where all the hadrons have gone," he said thoughtfully.
So far this is one of the most mysterious enigma in the hadron physics.
At lower baryon chemical potential, that is, [[mu].sub.B] = 0 MeV, the effect of interaction among hadrons is negligible on particle ratio [LAMBDA]/[[pi].sup.-] even for relatively high temperature of T = 150 MeV.
The IBM effort represents the first full calculation of hadron masses from QCD, Weingarten says.
We can extrapolate the validity of this parametrization further for the produced charged particles in hadron-nucleus interactions by considering multiple collisions suffered by the quarks of hadrons in the nucleus.
We also assume Boltzmann distributions for all hadrons. The multiplicity of a given scalar hadronic species j then becomes
Uddin et al., "Transverse Momentum Distributions of Hadrons Produced in Pb-Pb Collisions at LHC Energy [square root of ([s.sub.NN])] = 2.76 TeV," Advances in High Energy Physics, vol.
"In particular, the new results show that the production rate of these strange hadrons increases with the 'multiplicity' 6 the number of particles produced in a given collision 6 faster than that of other particles generated in the same collision," CERN explained in the statement.
In this situation the free quarks disappear, they become condensed in the hadrons. So the role of the potential is reducing the number of free quarks.
"I mean, when you've got a large hadron collider, there's not really so much you can do apart from colliding large hadrons.
Though they are phenomena at different levels of subatomic organization, hadrons and nuclei are both governed by the strong interaction and are eventually described by quantum chromodynamics, so there is much that members of the two research fields can share, most notably, chiral symmetry and pions.