September
01
Properties of
Nucleons
Masses mp = 938.279
MeV/c2
mn =
939.573 MeV/c2
Charges ep = +|e| en = 0
proton
neutron
Spins (mechanical) Sp = ½ ħ Sn = ½ ħ
Nucleons are Fermions
Each has 2 possible
orientations in space: spin-up or spin-down
mn, mp = ±½
Neutrons and protons are
very similar, with similar interactions. Consider
them as 2 different realizations of the nucleon: isospin-up
or isospin-down tz(n)
=
+½, tz(p)
= -½
Isospin
T is a hypothetical order parameter(vector).
