What is the Value of Fermi's Constant (GF) in SI Units?

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Discussion Overview

The discussion revolves around the value of Fermi's constant (GF) in SI units, with participants exploring calculations, conversions, and clarifications related to its value and units. The scope includes theoretical and mathematical reasoning.

Discussion Character

  • Technical explanation, Mathematical reasoning, Debate/contested

Main Points Raised

  • One participant inquires about the value of Fermi's constant (GF) in SI units and presents their own calculated value of 6.5 x 1041 J-2.
  • Another participant provides a value from a Google calculator, stating GF = 4.54376275 x 1014 J-2 and relates it to a conversion involving GeV-2.
  • A subsequent post seeks clarification on whether the provided value refers to GF divided by a product of constants, not GF itself.
  • One participant expresses uncertainty about converting GF to cgs units and asks for guidance on using Google for unit conversion.
  • Another participant suggests that if the value is known in Joules, it can be converted to ergs easily.
  • A final post introduces a different expression for GF, stating Gf2 = 5.29 x 10-38 cm2/GeV2.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the exact value of Fermi's constant or the method of conversion, indicating multiple competing views and uncertainty in calculations.

Contextual Notes

Some calculations and conversions are presented without clear assumptions or definitions, and there is ambiguity regarding the relationship between GF and other constants.

randa177
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what is the value of fermi's constant ( GF ) in SI units?
I tried to work it out, but it seems that I'm wrong, I got a value of: 6.5 X 10(41) J(-2)

Does it make sense?
 
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Google calculator gives:

[tex] G_F = 4.54376275 \times 10^{14} J^{-2}[/tex]

where

[tex] \frac{G_F}{(\hbar c)^3} = 1.16637 \times 10^{-5} GeV^{-2}[/tex]

I used the following code in Google:

Code:
1.16637*10^-5 (GeV)^-2 in (Joules)^-2
 
so, you mean Gf / (h.bar X c) ^ 3 = 4.5 X 10 (14),,, [ not the Gf itself] right?
 
how to get it in cgs units,,, I don't know how to use google to convert the units!
 
If you know it in Joules, just convert Joules to ergs.
You can do it in your head if google fails you.
 
what is then Gf2=5.29 * 10-38 cm2/GeV2?
 

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