isospin
Sign in to saveIn nuclear physics and particle physics, isospin is a quantum number related to the up- and down quark content of the particle. Isospin is also known as isobaric spin or isotopic spin. Isospin symmetry is a subset of the flavour symmetry seen more broadly in the interactions of baryons and mesons.
Article
16 sectionsContents
- Isospin invariance
- Relation to hypercharge
- Quark content and isospin
- Isospin and symmetry
- Hadron nomenclature
- History
- Origin of isospin
- The particle zoo
- An example: Delta baryons
- Gauged isospin symmetry
- The introduction of quarks
- Weak isospin
- References
- Further reading
- See also
- External links
In nuclear physics and particle physics, isospin is a quantum number related to the up- and down quark content of the particle. Isospin is also known as isobaric spin or isotopic spin. Isospin symmetry is a subset of the flavour symmetry seen more broadly in the interactions of baryons and mesons.
The name of the concept contains the term spin because its quantum mechanical description is mathematically similar to that of angular momentum (in particular, in the way it couples; for example, a proton–neutron pair can be coupled either in a state of total isospin 1 or in one of 0). But unlike angular momentum, it is a dimensionless quantity and is not actually any type of spin.