# Weak coupling strength constant

1. Sep 22, 2009

### neelakash

When it is said that the relative strength of weak interaction is $$\ 10^{-5}$$,what does this mean?

On calculation I am getting $$\alpha_w=\10^{-3}$$ with $$\ G_F=\ 1.16\times\ 10^{-5} \ GeV^{-2}$$

I had an impression that $$\alpha_w$$ should be $$\ 10^{-5}$$.Which one is correct?

2. Sep 22, 2009

### hamster143

"relative strength" is not a very well-defined concept. The ratio of weak to electromagnetic interaction strengths depends a lot on the energy scale.