Notation

Throughout this book we use ‘natural units’, i.e. we set ħ = c = 1. In this so-called natural unit system energy, mass and (length)⁻¹ all have the same dimension (unit GeV). To convert to conventional units, we multiply by an appropriate conversion factor, depending on ħ and c. For example, in the case of length, we multiply by ħc = 0.197 33 GeV · fermi (1 fermi = 1 femtometre = 10⁻¹⁵ m). Table N.1 Conventional units of mass, length and time expressed in terms of <italic>ħ</italic> = <italic>c</italic> = 1 energy units. See e.g. <xref ref-type="bibr" rid="ref11">Aitchison and Hey (1989</xref>) and <xref ref-type="bibr" rid="ref265">Halzen and Martin (1984</xref>).

Conversion factor

ħ = c = 1 units

Effective unit

1 kg = 5.61 · 10²⁶ GeV

GeV

GeV/c ²

1 m = 5.07 · 10¹⁵ GeV⁻¹

GeV⁻¹

ħc/GeV

1 s = 1.52 · 10²⁴ GeV⁻¹

GeV⁻¹

ħ/GeV