Parameters of the Standard Model (as of 2022)
Compilation of the parameters of the Standard-Model of particle physics:
| coupling constants | ||
|---|---|---|
| fine structure constant | α-1 | 137.035999084(21) |
| strong coupling constant | αs(MZ) | 0.1176(20) |
| gravitational constant | G | 6.70883(15)x10-39 GeV-2 |
| cosmological constant | Λ | 4.3(2)x10-84 GeV2 |
| boson masses | ||
| Z0 mass | MZ | 91.1876(21) GeV |
| W± mass | MW | 80.379(12) GeV |
| Higgs boson mass | MH | 125.10(14) GeV1 |
| lepton masses | ||
| electron mass | me | 0.51099895000(15)x10-3 GeV |
| muon mass | mμ | 0.1056583755(23) GeV |
| taon mass | mτ | 1.77686(12) GeV |
| quark masses | ||
| d mass | md | 2.16$^{+0.49}_{−0.26}$x10-3 GeV |
| u mass | mu | 4.67$^{+0.48}_{−0.17}$x10-3 GeV |
| s mass | ms | 93$^{+11}_{−5}$x10-3 GeV |
| c mass | mc | 1.27(2) GeV |
| b mass | mb | 4.18$^{+0.03}_{−0.02}$ GeV |
| t mass | mt | 172.9(2) GeV |
| Cabibo-Kobayashi-Maskawa mixing matrix2 | ||
| Cabibo angle | θ12 | 13.04±0.05° |
| Kobayashi angle | θ13 | 0.201±0.011° |
| Maskawa angle | θ23 | 2.38±0.06° |
| CP violating phase | δ13 | 68.8±4.5° |
| neutrino masses | ||
| average mass | ⅓(m1+m2+m3) | <2x10-9 GeV |
| solar splitting | m22-m12 | 8.0(4)x10-23 GeV2 |
| atmospheric splitting | m32-m22 | ±2.5(5)x10-23 GeV2 |
| Maki-Nakagawa-Sakata mixing matrix3[°] | ||
| solar mixing angle | θ12 | 33.44$^{+0.78}_{-0.75}$[°] |
| atmospheric mixing angle | θ23 | 49.0$^{+1.1}_{-1.4}$[°] |
| the third angle | θ13 | 8.57$^{+0.13}_{-0.12}$[°] |
| MNS phase | δCP | 195$^{+51}_{-25}$[°] |
One parameter may be eliminated by the choice of the unit of energy (i.e. electron mass instead of GeV). So, in total, there are at least 26 parameters in present day physics.
There may be more parameters in simple modifications of the Standard Model, i.e. 2 new phases in the NMS matrix if neutrinos are Majorana particles, or more than one Higgs boson mass is there are more then one Higgs, etc.
page revision: 21, last edited: 17 Feb 2022 07:32