All quarks carry an additive, conserved quantum number called a baryon number ( " B " ), which is + for quarks and " for antiquarks.
32.
In addition, the spectral asymmetry is interpreted as a non-zero vacuum expectation value of the baryon number, cancelling the topological winding number of the pion field surrounding the nucleon.
33.
Baryon number is accidentally conserved in the Standard Model ( see accidental symmetry ) but there's no known reason to expect non-SM objects like black holes to conserve it.
34.
The excess of baryons over antibaryons in the present universe is thought to be due to non-conservation of baryon number in the very early universe, though this is not well understood.
35.
The photon is the gauge boson for electromagnetism, and therefore all other quantum numbers of the photon ( such as lepton number, baryon number, and flavour quantum numbers ) are zero.
36.
The anomalies that would break baryon number conservation and lepton number conservation individually cancel in such a way that " B " " " L " is always conserved.
37.
Does it mean that the conservation of baryon number may have an extraneous, non-natural origin ( or, speaking more cautiously, contributes to the assumption of that extraneous imposition )?
38.
According to the Standard Model, protons, a type of baryon, are stable because baryon number ( quark number ) is conserved ( under normal circumstances; see chiral anomaly for exception ).
39.
Most grand unified theories explicitly break the baryon number symmetry, which would account for this discrepancy, typically invoking reactions mediated by very massive X bosons ( ) or massive Higgs bosons ( ).
40.
How does the baryon number, or quark fields, become a matter of topology and how would they cancel each other out ? talk ) 17 : 02, 2 August 2011 ( UTC)
