About recommended fine structure constant value

[sanko]

value of fine structure constant logarithmically depend upon momentum/energy scale.
so what is exact energy/momentum scale corresponds to standard/recommended value of fine structure constant?

 

[fzero]

The value published by the Particle Data Group is extrapolated to $$Q^2=0$$. Check http://pdg.lbl.gov/2010/reviews/rpp2010-rev-phys-constants.pdf

 

[sanko]

fzero thanks for reply , Q^2=0 is it any base value or it means zero momentum? its unlikely that it means zero momentum.

 

[Vanadium 50]

It means zero momentum.

 

[fzero]

I guess it's technically at the electron mass. I ran the value of $$\alpha(M_W)\sim 128$$ down and found agreement.