B − L
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In
quantum system
.
Details
This
U(1) symmetry in some Grand Unified Theory models, called U(1)B−L. Unlike baryon number alone or lepton number alone, this hypothetical symmetry would not be broken by chiral anomalies or gravitational anomalies
, as long as this symmetry is global, which is why this symmetry is often invoked.
If B – L exists as a symmetry, then for the
spontaneously broken to give the neutrinos
a nonzero mass.
The
conserved. One hypothetical example is proton decay where a proton (B = 1, L = 0) would decay into a pion (B = 0, L = 0) and positron
(B = 0, L = –1).
The weak hypercharge YW is related to B – L via
where
U(1) symmetry Grand Unified Theory.[1]
See also
- Baryogenesis
- Leptogenesis
- Majoron
- Proton decay
- X and Y bosons
- X (charge)
- Leptoquark
References
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