# Sign of g-factor value

1. Mar 31, 2007

### Amith2006

1. The problem statement, all variables and given/known data
1)I have a doubt regarding the sign of g factor value.
In Wikipedia the g-factors are given as:
Orbital g-factor
Mu(L) = g(L)[Mu(B)L]/h_bar
Where g(L)=-1 is the orbital g factor
Spin g-factor
Mu(S) = g(S)[Mu(B)S]/h_bar
Where g(S)=-2 is the spin g factor
Lande g-factor
Mu(J) = g(J)[Mu(B)J]/h_bar
Where g(J) is the spin g factor

But in my book it is given as follows:
Orbital g-factor
Mu(L) = -g(L)[Mu(B)L]/h_bar
Where g(L)=1 is the orbital g factor
Spin g-factor
Mu(S) = -g(S)[Mu(B)S]/h_bar
Where g(S)=2 is the spin g factor
Lande g-factor
Mu(J) = g(J)[Mu(B)J]/h_bar
Where g(J) is the spin g factor

Which is correct? Is the g factor positive or negative? Also, in Wikipedia it is given that the g-factor value for electrons, neutrons and muon is negative while it is positive for protons. I think they mean spin g-factor here.

2. Relevant equations

3. The attempt at a solution