Universal Constants

Overview
Constant Value Dimension Alias Definition & Notes
Universal constants used in too many categories to constrain their scope
Speed of light c 2.997 924 580 e+8 m.s-1 m/s Assigned
Permeability of vacuum μ0 12.566 370 614... e-7 kg.m.s-2.A-2 H/m | N/A2 = 4π.10-7. Assigned.
Permittivity of vacuum ε0 8.854 187 817... e-12 kg-1.m-3.s4.A2 F/m = 1 / (c2 μ0). Assigned.
Gravitation constant G 6.673 84[80] e-11 kg-1.m3.s-2 force = G M1M2 / r122
Planck constant h 6.626 069 57[29] e-34 kg.m2.s-1 J.s = (energy transfer quantum)/(channel frequency)
Angular Planck constant 1.054 571 726[47] e-34 kg.m2.s-1 J.s = h/2π, the angular momentum quantum
Charge/Quantum ratio 2.417 989 348[53] e+14 kg-1.m-2.s2.A A/J = e / h
Elementary charge e 1.602 176 565[35] e-19 s.A C
Quantum/Charge ratio 4.135 667 52[10] e-15 kg.m2.s-2.A-1 J/A = h / e
Fine structure constant α 7.297 352 5698[24] e-3 Dimensionless = μ0 c e2 / 2h.
Inverse of fine structure constant 137.035 999 074[45] Dimensionless = 1/α = 2h / (μ0 c e2). See ref.[1].
Boltzmann constant k 1.380 6488[13] e-23 kg.m2.s-2.K-1 J/K Sets thermodynamic temperature
Planck mass mp 2.176 51[13] e-8 kg mp2 = (h/2π) c / G
Planck time tp 5.391 06[32] e-44 s = (h/2π) / (mpc2)
Planck length lp 1.616 199[97] e-35 m = ctp
Planck temperature 1.416 833[85] e+32 K = mpc2 / k
Electromagnetic constants other than those already listed
Impedance of vacuum Z0 376.730 313 461 ... kg.m2.s-3.A-2 Ω Derived from assigned's: Z02 = μ0/ε0.
Magnetic flux quantum Φ0 2.067 833 758[46] e-15 kg.m2.s-2.A-1 Wb = h / 2e
Josephson constant KJ 4.835 978 70[11] e14 kg-1.m-2.s2.A Hz/V = 2e / h . Conventional: 483597.9 GHz/V
von Klitzing constant RK 2.581 280 744 34[84] e+4 kg.m2.s-3.A-2 Ω = h / e2. Conventional: 25812.807 Ω
Conductance quantum G0 7.748 091 7346[25] e-5 kg-1.m-2.s3.A2 S = 2e2 / h = 2 / RK
Inverse of conductance quantum 1.290 640 372 17[42] e+4 kg.m2.s-3.A-2 Ω = RK / 2
Electromagnetic radiation constants.
Stefan-Boltzmann const. σ 5.670 373[21] e-8 kg.s-3.K-4 W/m2.K4 = 2 π5 k4 / 15 h3 c2
1st radiation constant c1 3.741 771 53[17] e-16 kg.m4.s-3 W.m2 = 2 π h c2
2nd radiation constant c2 1.438 7770[13] e-2 m.K = h c / k
Wien λ displacement constant λmaxT 2.897 7721[26] e-3 m.K = c2 / 4.9651423...
Wien f displacement constant f/T 5.878 9254[53] e+10 s-1.K-1 Hz/K
Max. luminous efficacy: absolute 683 cd.sr.kg-1.m-1.s3 lm/W 100% efficient, ideal 555 nm light source.
Max. luminous efficacy: black-body 95 cd.sr.kg-1.m-1.s3 lm/W 7000 °K
Solar luminous efficacy 93 cd.sr.kg-1.m-1.s3 lm/W
Solar illuminance 1.280[10] e5 cd.sr.m-2 lx in the brightest sunlight, on Earth
Electron and atomic physics constants.
Rydberg constant R∞ 1.097 373 156 8539[55] e+7 m-1 m-1 = c α2 me / 2h
Hartree energy EH 4.359 744 34[19] e-18 kg.m2.s-2 J = α2 me c2 = 2h c R∞
Bohr radius 5.291 772 1092[17] e-11 m m = α / (4π R∞)
Bohr magneton μB 9.274 009 68[20] e-24 m2.A J/T = (1/2)(h/2π)(e/me)
Bohr magneton in Hz/T 1.399624555[31] e+10 kg-1.s.A Hz/T = μB/h = [Larmor frequency]/[g-factor]; ~ 14 GHz/T
Quantum of circulation 3.636 947 5520[24] e-4 m2.s-1 m2/s = h / 2me
Richardson constant 1.20173 e+6 A.m-2.K-2 = 4πemek2 / h3; arises in thermionic emission
Physico-chemical constants
Atomic mass constant u 1.660 538 921[73] e-27 kg Mass of 12C nuclide / 12
Molar mass of 12C 12 e-3 kg Assigned
Molar mass constant 1.0 e-3 kg.mol-1 kg/mol Assigned
Boltzmann constant k 1.380 6488[13] e-23 kg.m2.s-2.K-1 J/K Sets thermodynamic temperature
Boltzmann constant in eV/K 8.617 3324[78] e-5 kg.m2.s-3.A-1.K-1 V/K = k/e. Electrochemical potential ~ (k/e)T ln(c1/c2)
Avogadro's number NA 6.022 141 29[27] e+23 mol-1 count/mol ~ 602 Z (Zetta) particles in a mole of substance
Molar Planck constant 3.990 312 7176[28] e-10 kg.m2.s-1.mol-1 J.s/mol = h NA
Molar Planck constant by c 0.119 626 565 779[84] kg.m3.s-2.mol-1 J.m/mol = h c NA
Electron molar mass 5.485 799 0946[22] e-7 kg.mol-1 kg/mol = me NA
Electron molar charge - 9.648 533 65[21] e+4 s.A.mol-1 C/mol = e NA.
Faraday constant F +9.648 533 65[21] e+4 s.A.mol-1 C/mol = |electron molar charge|.
Molar gas constant R 8.314 4621[75] kg.m2.s-2.K-1.mol-1 J/K.mol = k NA
Molar volume of ideal gas Vm 22.413 968[20] e-3 m3.mol-1 m3/mol = (RT/p) at T=273.15 K, p=101325 Pa
Loschmidt constant n0 2.686 7805[24] e+25 m-3 count/m3 = NA / Vm at T=273.15 K, p=101325 Pa
Sackur-Tetrode constant S0/R - 1.164 8708[23] Dimensionless (5/2)+ln[(2πmukT/h2)(kT/p)] at T=1K, p=101325 Pa.
Basic nuclear physics data (those listed in CODATA)
Fermi coupling GF/(hc/2π)3 3.670 336[31] e+48 kg-2 = (1.026 8365[88] e-5) / mp2
Fermi coupling in eV-2 1.166 364[5] e+4 eV-2
Weak mixing angle sin2θW 0.2223[21] Dimensionless = 1- (mW/mZ)2
Nuclear magneton μN 5.050 783 53[11] e-27 m2.A J/T = (1/2)(h/2π)(e/mp)
Nuclear magneton in Hz/T 7.622 593 57[17] e+6 kg-1.s.A Hz/T = μN/h = [Larmor frequency]/[g-factor]; ~ 7.6 MHz/T
(baryon number 1/3, exist in u,c,t flavors, each has matter / anti-matter versions with some property flipped, spin 1/2, fermions)
u (up) quark rest energy (mc2) 3.8 e-13 kg.m2.s-2 J 2.4 MeV, stable
c (charm) quark rest energy (mc2) 2.03 e-10 kg.m2.s-2 J 1.27 GeV, unstable
t (top) quark rest energy (mc2) 2.743 e-8 kg.m2.s-2 J 171.2 GeV, terribly unstable
(baryon number 1/3, exist in d,s,b flavors, each has matter / anti-matter versions with some property flipped, spin 1/2, fermions)
d (down) quark rest energy (mc2) 7.7 e-13 kg.m2.s-2 J 4.8 MeV, stable
s (strange) quark rest energy (mc2) 1.67 e-11 kg.m2.s-2 J 104 MeV, unstable
b (bottom) quark rest energy (mc2) 6.7 e-10 kg.m2.s-2 J 4.2 GeV, unstable

Neucleons

Constant Value Dimension Alias Definition & Notes
Electron (stable lepton, charge -1, spin 1/2, fermion, its antiparticle positron has positive charge)
Electron rest mass me 9.109 382 91[40] e-31 kg = 5.485 799 0946[22] e-4 u
Electron rest energy (mec2) 8.187 105 06[36] e-14 kg.m2.s-2 J = 0.510 998 928[11] MeV
Electron charge/mass ratio - 1.758 820 088[39] e11 kg-1.s.A C/kg = e / me
Compton wavelength of electron λC,e 2.426 310 2389[16] e-12 m = h / c me
Classical electron radius re 2.817 940 3267[27] e-15 m = e2 / (4πε0mec2 )
Thomson cross section σe 0.665 245 8734[13] e-28 m2 = (8π/3) re2
Electron magnetic moment μe - 9.284 764 30[21] e-24 m2.A J/T
Electron g-factor ge - 2.002 319 304 361 53[53] Dimensionless = (μe / μB) / Se
Electron magnetic moment anomaly 1.159 652 180 76[27] e-3 Dimensionless = (abs(ge) - 2) / 2
Electron gyromagnetic ratio γe/2π 28.024 952 66[62] e+9 kg-1.s.A Hz/T = μe / (hSe); ~ 28 GHz/T
Electron/Proton mass ratio 5.446 170 2178[22] e-4 Dimensionless
Electron/Proton magnetic moments ratio - 658.210 6848[54] Dimensionless
Electron/Proton magnetic moments ratio - 658.227 597 1[72] Dimensionless Shielded in water; standard conditions
Proton (stable baryon, nucleon, hadron, charge +1, spin 1/2, fermion, parity +, isospin 1/2, its anti-particle antiproton has opposite charge)
Proton rest mass mp 1.672 621 777[74] e-27 kg 1.007 276 466 812[90] u
Proton rest energy (mc2) 1.503 277 484[66] e-10 kg.m2.s-2 J 938.272 046[21] MeV; quarks composition: uud
Proton / electron mass ratio 1836.15267245[75] Dimensionless inverse: 5.4461702178[22]e-4
Compton wavelength of proton λC,p 1.321 409 856 23[94] e-15 m λC,p = h / c mp
Proton rms charge radius 0.8775[51] e-15 m
Proton magnetic moment 1.410 606 743[33] e-26 m2.A J/T μp
Proton g-factor 5.585 694 713[46] Dimensionless = μp / (Sp μN)
Proton gyromagnetic ratio 42.577 4806[10] e+6 kg-1.s.A Hz/T γp = μp / h Sp.
Proton gyromagnetic ratio shielded 42.576 388 1[12] e+6 kg-1.s.A Hz/T In H2O, standard conditions
Proton magnetic shielding 25.694[14] e-6 Dimensionless Relative value for pure water at 25 °C
Electric dipole moment < 8.7 e-45 m.s.A C.m < 5.4 e-24 e.cm; existence not confirmed
Electric polarizibility 1.20[6] e-48 m3
Magnetic polarizibility 1.9[5] e-49 m3
Neutron (baryon, nucleon, hadron, charge 0, spin 1/2, fermion, parity +, isospin 1/2, its anti-particle is antineutron)
Neutron rest mass mn 1.674 927 351[74] e-27 kg 1.008 664 916 00[43] u
Neutron rest energy (mc2) 1.505 349 631[66] e-10 kg.m2.s-2 J 939.565 379[21] MeV; quarks composition udd
Compton wavelength of neutron λC,n 1.319 590 9068[11] e-15 m λC,n = h / c mn
Neutron half-life time 881.5[15] s Beta-decay into proton + e- + νe
Neutron magnetic moment - 0.966 236 47[23] e-26 m2.A J/T μn
Neutron g-factor - 3.826 085 45[90] Dimensionless = μn / (Sn μN)
Neutron gyromagnetic ratio 29.164 6943[69] e+6 kg-1.s.A Hz/T γn = μn / h Sn
Electric dipole moment < 4.6 e-47 m.s.A C.m < 2.9 e-26 e.cm; existence not confirmed
Electric polarizibility 1.16[15] e-48 m3
Magnetic polarizibility 3.7[20] e-49 m3
Deuteron (stable nuclide, protons 1, neutrons 1, charge +1, spin 1, boson)
Deuteron rest mass 3.343 583 48[15] e-27 kg 2.013 553 212 712[77] u
Deuteron rest energy (mc2) 3.005 062 97[13] e-10 kg.m2.s-2 J 1875.612 859[41] MeV
Deuteron rms charge radius 2.1424[21] e-15 m
Deuteron magnetic moment 0.433 073 489[10] e-26 m2.A J/T
Deuteron g-factor 0.857 438 2308[72] Dimensionless
Deuteron gyromagnetic ratio 6.535 903 381 41 e+6 kg-1.s.A Hz/T
Deuteron quadrupole moment 4.581 e-50 m2.s.A C.m2 0.2859 e(fm)2
Triton (stable nuclide, protons 1, neutrons 2, charge +1, spin 1/2, fermion)
Triton rest mass 5.007 356 30[22] e-27 kg 3.015 500 7134[25] u
Triton rest energy (mc2) 4.500 387 41[20] e-10 kg.m2.s-2 J 2808.921 005[62] MeV
Triton half-life time 3.888[70] e+8 s = 12.32 years; beta-decay into 3He + e- + νe
Triton magnetic moment 1.504 609 447[38] e-26 m2.A J/T
Triton g-factor 5.957 924 896[76] Dimensionless
Triton gyromagnetic ratio 45.413 674 6[13] e+6 kg-1.s.A Hz/T
Helion (stable nuclide, protons 2, neutrons 1, charge +2, spin 1/2, fermion, nuclide)
Helion rest mass 5.006 412 34[22] e-27 kg 3.014 932 2468[25] u
Helion rest energy (mc2) 4.499 539 02[20] e-10 kg.m2.s-2 J 2808.391 482[62] MeV
Helion magnetic moment - 1.074 617 486[27] e-26 m2.A J/T Shielded
Helion g-factor - 4.255 250 613[50] Dimensionless
Helion gyromagnetic ratio 32.434 101 98[90] e+6 kg-1.s.A Hz/T Shielded
Alpha particle (stable nuclide, protons 2, neutrons 2, charge +2, spin 0, magnetic moment 0, boson)
α-particle rest mass 6.644 656 75[29] e-27 kg 4.001 506 179 125[62] u
α-particle rest energy (mc2) 5.971 919 67[26] e-10 kg.m2.s-2 J 3727.379 240[82] MeV
Particle physics data (source: Particle Data Group)
(stable leptons, charge 0, exist in e,μ,τ flavors, each has matter / anti-matter version with opposite chirality, spin 1/2, fermions)
Electron neutrino νe rest energy (mc2) max 3.5 e-13 kg.m2.s-2 J 0 to 2.2 MeV; possibly 0
Muon neutrino νμ rest energy (mc2) max 0.27 e-13 kg.m2.s-2 J 0 to 0.17 MeV; possibly 0
Tau neutrino ντ rest energy (mc2) max 24.8 e-13 kg.m2.s-2 J 0 to 15.5 MeV; possibly 0
Muon μ± (lepton, charge ±1, matter μ-, antimatter μ+, spin 1/2, fermion)
Muon rest energy (mc2) 1.692 833 667[86] e-11 kg.m2.s-2 J 105.658 3715[35] MeV
Muon rest mass 1.883 531 475[96] e-28 kg 0.113 428 9267[29] u
Muon magnetic moment - 4.490 448 07[15] e-26 m2.A J/T
Muon g-factor gμ - 2.002 331 8418[13] Dimensionless (μ / μB) * (m / me) / spin
Muon magnetic moment anomaly 1.165 920 91[63] e-3 Dimensionless (abs(gμ) - 2) / 2
Muon gyromagnetic ratio 135.538 817[12] e+6 kg-1.s.A Hz/T = μn / h Sn
Muon half-life time 1.52 e-6 s
Tau τ± (lepton, charge ±1, matter τ-, antimatter τ+, spin 1/2, fermion)
Tau rest energy (mc2) 2.846 78[26] e-10 kg.m2.s-2 J 1776.82[16] MeV
Tau rest mass 3.167 47[29] e-27 kg 1.907 49[17] u
Tau half-life time 2.9 e-13 s

Other Baryons and Resonance Particles

Constant Value Dimension Alias Definition & Notes
Pions π± (mesons, hadrons, charge ±1, anti-particles of each other, spin 0, boson, parity -, isospin 1)
Pions π± rest energy (mc2) 2.236 1607[56] e-11 kg.m2.s-2 J 139.570 18[35] MeV
Pions π± rest mass 2.488 0643[62] e-28 kg 0.149 834 75[37] u
Pions π± half-life time 2.6 e-8 s quarks composition: π+: ud', π-: du'
Pion π0 (meson, hadron, charge 0, its own antiparticle, spin 0, boson, parity -,C-parity +, isospin 1)
Pion π0 rest energy (mc2) 2.162 5634[96] e-11 kg.m2.s-2 J 134.976 60[60] MeV
Pion π0 rest mass 2.406 176[11] e-28 kg 0.144 903 34[64] u
Pion π0 half-life time 8.4 e-17 s quarks composition: (uu'-dd')/&radiv;2
Kaons K± ('strange' mesons, hadrons, charge ±1, anti-particles of each other, spin 0, boson, parity -, isospin 1/2)
Kaons K± rest energy (mc2) 7.909 58[26] e-11 kg.m2.s-2 J 493.677[16] MeV
Kaons K± rest mass 8.800 591[29] e-28 kg 0.529 984[17] u
Kaons K± half-life time 1.2380[21] e-8 s quarks composition: K+: us', K-: su'
Kaon K0 ('strange' meson, hadron, charge 0, self-antiparticle, spin 0, boson, isospin 1/2, parity -)
Kaon K0 rest energy (mc2) 7.972 65[38] e-11 kg.m2.s-2 J 497.614[24] MeV; quarks: see below
Kaon K0 rest mass 8.870 77[42] e-28 kg 0.534 211[26] u
Kaon K0L half-life time (long) 5.116[20] e-8 s quarks composition: (ds'+sd')/√2
Kaon K0S half-life time (short) 8.953[5] e-11 s quarks composition: (ds'-sd')/√2
Eta mesons η and η' (hadrons, charge 0, antiparticles of each other, spin integer, bosons,
η rest energy (mc2) 8.777 57[38] e-11 kg.m2.s-2 J 547.853[24] MeV
η rest mass 9.766 36[42] e-28 kg 0.588 144[25] u
η half-life time 5.0[3] e-19 s quarks composition: (uu'+dd'-2ss')/√6
η' rest energy (mc2) 1.53434[38] e-10 kg.m2.s-2 J 957.66[24] MeV
η' rest mass 1.70718[43] e-27 kg 1.02809[26] u
η' half-life time 3.2[2] e-21 s quarks composition: (uu'+dd'+ss')/√3
(baryons, charge 0 or +1, spin 1/2, fermions, parity +; predicted only: top Λt+, quarks udt, but t-quark decays before it hadronizes)
Λ0 rest energy (mc2) 1.7875211[96] e-10 kg.m2.s-2 J 1.1156830[60] GeV; charge 0
Λ0 rest mass 1.988885[11] e-27 kg 1.1977349[64] u
Λ0 half-life time 2.631[20] e-10 s quarks composition: uds
Bottom Λ0b rest energy (mc2) 9.0046[26] e-10 kg.m2.s-2 J 5.6202[16] GeV; charge 0
Bottom Λ0b rest mass 1.00189[29] e-26 kg 6.0335[17] u
Bottom Λ0b half-life time 1.409[55] e-12 s quarks composition: udb
Charmed Λ+c rest energy (mc2) 3.66331[22] e-10 kg.m2.s-2 J 2.28646[14] GeV; charge +1
Charmed Λ+c rest mass 4.07599[25] e-27 kg 2.45462[15] u
Charmed Λ+c half-life time 2.000[60] e-13 s quarks composition: udc
(barions, charge -1, 0, +1 or +2, fermions, parity +; predicted only: udb, uut, udt, ddt)
Σ+ rest energy (mc2) 1.90558[11] e-10 kg.m2.s-2 J 1.189370[70] GeV; charge +1
Σ+ rest mass 2.12024[12] e-27 kg 1.276841[75] u
Σ+ half-life time 8.018[26] e-11 s quarks composition: uus
Σ0 rest energy (mc2) 1.910823[38] e-10 kg.m2.s-2 J 1.192642[24] GeV; charge 0
Σ0 rest mass 2.126077[43] e-27 kg 1.280353[26] u
Σ0 half-life time 7.40[70] e-20 s quarks composition: uds
Σ- rest energy (mc2) 1.918525[48] e-10 kg.m2.s-2 J 1.197449[30] GeV; charge -1
Σ- rest mass 2.13465[53] e-27 kg 1.285514[32] u
Σ- half-life time 1.479[11] e-10 s quarks composition: dds
Charmed Σc++ rest energy (mc2) 3.93177[29] e-10 kg.m2.s-2 J 2.45402[18] GeV; charge +2
Charmed Σc++ rest mass 4.37469[32] e-27 kg 2.63450[19] u
Charmed Σc++ half-life time 3.00[40] e-22 s quarks composition: uuc
Charmed Σc+ rest energy (mc2) 3.92998[64] e-10 kg.m2.s-2 J 2.45290[40] GeV; charge +1
Charmed Σc+ rest mass 4.37269[71] e-27 kg 2.63330[43] u
Charmed Σc+ half-life time >1.4 e-22 s quarks composition: udc
Charmed Σc0 rest energy (mc2) 3.93136[29] e-10 kg.m2.s-2 J 2.45376[18] GeV; charge 0
Charmed Σc0 rest mass 4.37422[32] e-27 kg 2.63422[19] u
Charmed Σc0 half-life time 3.0 e-22 s quarks composition: ddc
Bottom Σb+ rest energy (mc2) 9.3051[62] e-10 kg.m2.s-2 J 5.8078[39] GeV; charge +1
Bottom Σb+ rest mass 1.03533[69] e-26 kg 6.2349[42] u
Bottom Σb+ half-life time ? s quarks composition: uub
Bottom Σb- rest energy (mc2) 9.3170[43] e-10 kg.m2.s-2 J 5.8152[27] GeV; charge -1
Bottom Σb- rest mass 1.03665[48] e-26 kg 6.2429[30] u
Bottom Σb- half-life time ? s quarks composition: ddb
(barions, charge -1, 0, +1 or +2, fermions, parity +; predicted only: uub, udb, ddb, uut, udt, ddt)
Σ*+ rest energy (mc2) 2.21549[64] e-10 kg.m2.s-2 J 1.38280[40] GeV; charge +1
Σ*+ rest mass 2.46506[71] e-27 kg 1.48450[43] u
Σ*+ half-life time 1.840[40] e-23 s quarks composition: uus
Σ*0 rest energy (mc2) 2.21693[16] e-10 kg.m2.s-2 J 1.38370[10] GeV; charge 0
Σ*0 rest mass 2.46667[18] e-27 kg 1.48546[11] u
Σ*0 half-life time 1.80[30] e-23 s quarks composition: uds
Σ*- rest energy (mc2) 2.22254[80] e-10 kg.m2.s-2 J 1.38720[50] GeV; charge -1
Σ*- rest mass 2.47291[89] e-27 kg 1.48922[54] u
Σ*- half-life time 1.670[90] e-23 s quarks composition: dds
Charmed Σ*++c rest energy (mc2) 4.03492[96] e-10 kg.m2.s-2 J 2.51840[60] GeV; charge +2
Charmed Σ*++c rest mass 4.4894[11] e-27 kg 2.70361[64] u
Charmed Σ*++c half-life time 4.40[60] e-23 s quarks composition: uuc
Charmed Σ*+c rest energy (mc2) 4.0335[37] e-10 kg.m2.s-2 J 2.5175[23] GeV; charge +1
Charmed Σ*+c rest mass 4.4879[41] e-27 kg 2.7026[25] u
Charmed Σ*+c half-life time > 3.9 e-23 s quarks composition: udc
Charmed Σ*0c rest energy (mc2) 4.03428[80] e-10 kg.m2.s-2 J 2.518 GeV; charge 0
Charmed Σ*0c rest mass 4.48874[89] e-27 kg 2.70318[54] u
Charmed Σ*0c half-life time 4.10[50] e-23 s quarks composition: ddc
(barions, charge -1, 0, +1, spin 1/2, fermions, parity +; predicted only: ucc, ubb, dbb, ucb, dcb)
Ξ0 rest energy (mc2) 2.106638[32] e-10 kg.m2.s-2 J 1.31486[20] GeV; charge 0
Ξ0 rest mass 2.34395[35] e-27 kg 1.41156[21] u
Ξ0 half-life time 2.900[90] e-10 s quarks composition: uss
Ξ- rest energy (mc2) 2.11697[21] e-10 kg.m2.s-2 J 1.32131[13] GeV; charge -1
Ξ- rest mass 2.35544[23] e-27 kg 1.41848[14] u
Ξ- half-life time 1.639[15] e-10 s quarks composition: dss
Charmed Ξc+ rest energy (mc2) 3.95401[64] e-10 kg.m2.s-2 J 2.46790[40] GeV; charge +1
Charmed Ξc+ rest mass 4.39943[71] e-27 kg 2.64940[43] u
Charmed Ξc+ half-life time 4.42[26] e-13 s quarks composition: usc
Charmed Ξc0 rest energy (mc2) 3.95898[64] e-10 kg.m2.s-2 J 2.47100[40] GeV; charge 0
Charmed Ξc0 rest mass 4.40496[71] e-27 kg 2.65273[43] u
Charmed Ξc0 half-life time 1.12[13] e-13 s quarks composition: dsc
Double charmed Ξcc+ rest energy (mc2) 5.6379[14] e-10 kg.m2.s-2 J 3.51890[90] GeV; charge +1
Double charmed Ξcc+ rest mass 6.2730[16] e-27 kg 3.77769[97] u
Double charmed Ξcc+ half-life time < 3.3 e-14 s quarks composition: dcc
Bottom Ξb0 rest energy (mc2) 9.2798[48] e-10 kg.m2.s-2 J 5.7920[30] GeV; charge 0
Bottom Ξb0 rest mass 1.0325[53] e-26 kg 6.2180[32] u
Bottom Ξb0 half-life time 1.42[28] e-12 s quarks composition: usb
Bottom Ξb- rest energy (mc2) 9.2815[48] e-10 kg.m2.s-2 J 5.7929[30] GeV; charge -1
Bottom Ξb- rest mass 1.0335[53] e-26 kg 6.2191[32] u
Bottom Ξb- half-life time 1.42[28] e-12 s quarks composition: dsb
Ξ resonances: {uss, S=3/2, 1.53180[32] GeV}, {dss, S=3/2, 1.53500[60] GeV}, {usc, S=1/2, 2.57570[31] GeV}, {dsc, S=1/2, 2.57800[29] GeV, 1.1e-13 s},
(barions, charge -1 or 0, spin 1/2 or 3/2, fermions, parity +; predicted only: scc, scb, sbb, ccc, ccb, cbb, bbb)
Ω- rest energy (mc2) 2.67956[46] e-10 kg.m2.s-2 J 1.67245[29] GeV; charge -1, spin 3/2
Ω- rest mass 2.98141[52] e-27 kg 1.79544[31] u
Ω- half-life time 8.21[11] e-11 s quarks composition: sss
Charmed Ω0c rest energy (mc2) 4.3219[41] e-10 kg.m2.s-2 J 2.6975[26] GeV; charge 0, spin 1/2
Charmed Ω0c rest mass 4.8087[28] e-27 kg 2.8959[28] u
Charmed Ω0c half-life time 6.9[12] e-14 s quarks composition: ssc
Bottom Ω-b rest energy (mc2) 9.700[11] e-10 kg.m2.s-2 J 6.0544[68] GeV; charge -1, spin 1/2
Bottom Ω-b rest mass 1.0793[12] e-26 kg 6.49967[73] u
Bottom Ω-b half-life time 1.13[53] e-12 s quarks composition: ssb

Intermediate Vector Bosons
Higgs Particle

Constant Value Dimension Alias Definition & Notes
(charge 0, spin 1)
Z boson rest energy (mc2) 1.460986[33] e-8 kg.m2.s-2 J 91.1876[21] GeV
Z boson rest mass 1.625566[37] e-25 kg 97.8939[23] u
(charge 0, spin 0, predicted only, not found)
H0 rest energy (mc2) 1.95[13] e-8 kg.m2.s-2 J 122[8] GeV; theoretical data only!
H0 rest mass 2.1748474509 e-25 kg 131[9] u

Constants & Conversion Factors

Conventional constants
Molar mass constant 0.001 kg.mol-1 kg/mol Assigned (exact)
Molar mass of 12C 0.012 kg Assigned (exact)
Standard gravity acceleration 9.806 65 m.s-2 m/s2 Assigned. Called 1 g (gee).
Standard atmosphere 101 325 Pa Assigned. Called 1 atm .
Stellar magnitudes. Reference points: Apparent brightness: bolometric, initially Vega was 0 (now it is +0.03). Absolute: the Sun is 4.83 (used to be 4.75)
Stellar apparent magnitude unit 2.511 886 431 509 580 ... Dimensionless a ratio 1001/5 = 100.4; also stellar brightness
Stellar absolute magnitude unit 2.511 886 431 509 580 ... Dimensionless a ratio Brightness of a star when distant 10 parsecs
Conventional engineering constants. See also Math constants pertinent to Engineering definitions.
dBm
0 dBm power 0.001 kg.m2.s-3 Watts 1 mW; assigned
0 dBm potential 0.774 596 669 241 483 ... kg.m2.s-3.A-1 Volts 1 mW into 600 Ohm load
0 dBm current 0.001 290 994 448 736 ... A Amperes 1 mW into 600 Ohm load
dBW
0 dBW power 1.0 kg.m2.s-3 Watts 1 W; assigned
0 dBW potential 7.071 067 811 865 475 ... kg.m2.s-3.A-1 Volts sqrt(Z0); 1 W into 50 Ohm load Z0
0 dBW current 0.141 421 356 237 310 ... A Amperes sqrt(1/Z0); 1 W into 50 Ohm load Z0
Conversion of dBW into dBm (additive) +30 Dimensionless dB In terms of power
Relative luminance Y of RGB color primaries: Y = 0.2126.R + 0.7152.G + 0.0722.B. More info...
Relative luminance of Red/RGB 0.2126 Dimensionless a ratio
Relative luminance of Green/RGB 0.7152 Dimensionless a ratio Human eye is most sensitive to green
Relative luminance of Blue/RGB 0.0722 Dimensionless a ratio
Music and acoustics
Frequency of the A4 reference note 440.0 s-1 Hz ISO 16
Full-octave frequency ratio 2.0 exact Dimensionless Ratio C,C#,D,D#,E,F,F#,G,G#,A,A#,B,...next C
Half-tone frequency ratio 21/12 1.059 463 094 359 295 ... Dimensionless Ratio 12 half-tones per octave, each worth 100 cents
Conversion factors for entities tolerated by SI, as well as some others
Energy & its equivalents
Electron volt 1.602 176 565[35] e-19 kg.m2.s-2 J Basic eV-to-SI conversion
Electron volt to mass 1.782 661 845[39] e-36 kg mass = energy/c2
Electron volt to atomic units u 1.073 544 150[24] e-9 - u a mass equivalent
Electron volt to frequency 2.417 989 348[53] e+14 s-1 Hz frequency = energy/h
Joul to eV 6.241 509 34[14] e+18 - eV Basic SI-to-eV conversion
Mass to eV 5.609 588 85[12] e+35 - eV energy = mass.c2
Atomic unit u to eV 931.494 061[21] e+6 - eV a bit less than 1 GeV/atomic_unit
Frequency (1 Hz) to eV 4.135 667 516[91] e-15 - eV energy = frequency*h
Atomic mass constant u, mu 1.660 538 921[73] e-27 kg Mass of 12C nuclide / 12
Atomic mass energy (uc2) 1.492 417 954[66] e-10 kg.m2.s-2 J 931.494 061[21] MeV
Length / Distance
Astronomical unit ua, au 1.49597870[30] e+11 m ~150 Gm Mean Earth-to-Sun distance
Light-year -- ly 9.4607304725808 e+15 m ~9.5 Pm Exact: light covers it in one Julian year
Parsec -- pc (~ 3.26 ly) 3.08567757[60] e+16 m ~30 Pm Corresponds to au parallax of 1 second
Time
Hour 3.600 e+3 s Exact: 3600 seconds
Day 8.6400 e+4 s Exact: 24 hours
Julian year 3.1557600 e+7 s Exact: 365.25 days
Gregorian year (mean) 3.1556952 e+7 s Exact: 365.2425 days
Tropical year (drops ~0.53 s/century) 3.155692518747072 e+7 s 365.2421896698 days in year 2000
Plane and solid angles
1 radian in degrees 5.729577951308232... e+1 Dimensionless °, degree 180/π; planar angle; 57° 17' 44.806247...''
1° degree in radians 1.745329251994330... e-2 Dimensionless rad π/180; planar angle
1' minute in radians 2.908882086657215 ... e-4 Dimensionless rad π/180/60; planar angle
1'' second in radians 4.848136811095359 ... e-6 Dimensionless rad π/180/60/60; planar angle
1 steradian in degree2 3.282806350011744... e+3 Dimensionless degree2 (180/π)2; for solid angle infinitesimals
1 degree2 in steradians 3.046174197867086... e-4 Dimensionless2 sr (π/180)2; for solid angle infinitesimals

Miscellaneous Equations

B-V Color

Degrees-Radians

Distance

DistanceMod





FaintDetect


HubbleLaw

MagnitudeBrightnessRelation

RecessionalV

RedShift

RelativisticRedshift

Resolution


SchwarzchildRadius

SmallAngleFormula

StefanBoltzmann

TelescopeMagnification

TidalForceEarthMoon

WeinsLaw