Formulae and Data for Particle Physics

Constants

 Constant Physics Code Value Units Speed of Light c 3 × 108 m/s Planck’s Constant h 6.63 × 10-34 Js Charge on an electron e 1.60 × 10-19 C Mass of an electron me 9.11 × 10-31 kg Mass of a proton mp 1.673 × 10-27 kg Mass of a neutron mn 1.675 × 10-27 kg

Formulae

Energy of a Photon

E = hf

[E – energy in joules (J); f – frequency (Hz); h – Planck’s constant (Js)]

Alternatively:

[E – energy in joules (J); h – Planck’s constant (Js); l – wavelength (m); c – speed of light (m/s)]

Einstein’s Mass and Energy Equation

E = mc2

[E – energy in joules (J); m – mass (kg);  c – speed of light (m/s)]

Charge/mass ratio (charge per kilogram)

Ratio

[Q – charge in coulombs (C); m – mass (kg)]

To convert joules to electron volts (eV)

Energy (eV) = Energy (J) ÷ 1.60 × 10-19 (J/eV)

To convert eV to joules

Energy (J) = Energy (eV) × 1.60 × 10-19 (J/eV)

Conversions

 Prefix Symbol Multiplication Factor Example Tera- T × 1012 14 TeV Ultra high energy Giga- G × 109 5 GeV high energy particles Mega- M × 106 Rest energy of electron is 0.511 MeV kilo- k × 103 1 kg calcium sulphate milli- m × 10-3 Track of an alpha particle is 3 mm micro- m × 10-6 A strange baryon lasts 2 ms nano- n × 10-9 X-rays have a wavelength of 0.1 nm femto- f × 10-15 Radius of a proton is about 1 fm atto- a × 10-18 Range of weak force is about 1 am

You need to know the ones in bold.

Properties of Particles

Leptons (light things)

 Lepton Symbol Charge (e) Rest mass (MeV) Lepton Number (Le) Lepton Number (Lm) Baryon number Electron e- -1 0.511 1 0 0 Electron neutrino ne 0 2.2 eV 1 0 0 Muon m- -1 105 0 1 0 Muon neutrino nm 0 170 keV 0 1 0 Electron e+ +1 0.511 -1 0 0 Electron antineutrino e 0 2.2 eV -1 0 0 Antimuon +1 105 0 -1 0 Muon antineutrino 0 170 keV 0 -1 0

e = 1.60 ×10-19 C.  m – “mu”, a Greek letter ‘m’; n – “nu”, a Greek letter ‘n’.

Quarks

 Quark Symbol Charge (e) Rest mass (MeV) Baryon Number Lepton Number Strangeness up u +2/3 2.4 +1/3 0 0 down d -1/3 4.8 +1/3 0 0 strange s -1/3 104 +1/3 0 -1 anti up -2/3 2.4 -1/3 0 0 anti-down d +1/3 4.8 -1/3 0 0 anti-strange s +1/3 104 -1/3 0 +1

Other than that they exist, you don’t need to know about charm, top, or bottom.