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.