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I am attempting to calculate the mass of the W boson according to one loop energies using the equation,

M_{w}^{2}=(πα/G_{F}√2)/sin^{2}θ_{w}(1-Δr)

where (Δr)_{top}=(3G_{F}M_{t}^{2})/8√2π^{2}tan^{2}θ_{w}

using values:-

α=α(M_{Z})=(127.916)^{-1}

G_{F}=1.16634×10^{-5}

sin^{2}θw=0.23116 => tan^{2}θw=sin^{2}θw/cos^{2}θw=sin^{2}θw/(1-sin^{2}θw)=0.300661

M_{t}=172.9

This gives the result M_{w}=72.2922, which is very wrong.

I suspect at least part of the discrepancy comes from the fact that the Tree Level Fermi Constant has been used, yet many hours of scouring the Internet has not revealed any running values of it. Is my assumption correct, or is there something more fundamentally wrong with what I have done?

I appreciate any assistance you can lend.

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# One loop Fermi Constant running

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