|
Symbol
|
Value[1] (SI units)
|
Relative Standard Uncertainty
|
Bohr radius
|
|
5.291 772 108(18) × 10−11 m
|
3.3 × 10−9
|
classical electron radius
|
|
2.817 940 2894(58) × 10−15 m
|
2.1 × 10−9
|
electron mass
|
|
9.109 382 15(45) × 10−31 kg
|
5.0 × 10−8
|
Fermi coupling constant
|
|
1.166 39(1) × 10−5 GeV−2
|
8.6 × 10−6
|
fine-structure constant
|
|
7.297 352 537 6(50) × 10−3
|
6.8 × 10−10
|
Hartree energy
|
|
4.359 744 17(75) × 10−18 J
|
1.7 × 10−7
|
proton mass
|
|
1.672 621 637(83) × 10−27 kg
|
5.0 × 10−8
|
quantum of circulation
|
|
3.636 947 550(24) × 10−4 m² s−1
|
6.7 × 10−9
|
Rydberg constant
|
|
10 973 731.568 525(73) m−1
|
6.6 × 10−12
|
Thomson cross section
|
|
6.652 458 73(13) × 10−29 m²
|
2.0 × 10−8
|
weak mixing angle
|
|
0.222 15(76) |
3.4 × 10−3
|