baryon number

American  

noun

Physics.

1. a quantum number assigned to elementary particles, baryons having baryon number 1, antibaryons −1, and all other observable particles 0; quarks have baryon number 1/3 and antiquarks −1/3.

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baryon number Scientific  

1. A quantum number equal to the number of baryons in a system of subatomic particles minus the number of antibaryons. Baryons have a baryon number of +1, while antibaryons have a baryon number of −1. Quarks and antiquarks have baryon numbers of + 1/3 and − 1/3, respectively (baryons consists of three quarks). Mesons, bosons, and leptons all have baryon numbers of 0. Although the baryon number has always remained unchanged in reactions observed in experiments, it is postulated that in interactions that take place under conditions of very high energies (as during the formation of the universe, for example), proton decay may take place, and baryon number conservation may be violated.

2. See also isospin strangeness

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Example Sentences

See Examples For:

baryon number

In that picture, a proton has a baryon number of plus one, divided equally among its three main valence quarks.

From Science Daily ● Aug. 16, 2026

If confirmed, that would challenge the long-standing assumption that baryon number belongs exclusively to those quarks.

From Science Daily ● Aug. 16, 2026

If valence quarks alone carried the baryon number, explaining the excess away from the beamline would require all three valence quarks from one colliding proton to stop near the center of the detector.

From Science Daily ● Aug. 16, 2026

A new physical quantity called baryon number B seems to always be conserved in nature and is listed for the various particles in the table given above.

From Textbooks ● Aug. 12, 2015

The conservation of total baryon number is a more general rule than first noted in nuclear physics, where it was observed that the total number of nucleons was always conserved in nuclear reactions and decays.

From Textbooks ● Aug. 12, 2015