Introduction:
Fundamental Building Blocks of Matter


 The Standard Model
The Standard Model is a description of all fundamental particles and the forces between them. Fundamental particles are the smallest possible particles - they are not composed of anything smaller. There are three types of fundamental particle, quarks, leptons and bosons. These particles make up everything in the universe. Each particle has a corresponding anti-particle of equal mass and opposite charge.


 Quarks & Antiquarks

There are six types ('flavours') of quark, organized into three families ('generations'). The charge Q of each quark is quoted as a fraction of the elementary charge, e = 1.609 x 10-19 Coulombs.

The quark table below describes the flavours and illustrates how the quarks are organized into generations.

The anti-quark table is very similar.

The general symbol for a quark is , and that of antiquark is .

Quarks cannot exist on their own. They are bound in groups of two or three in particles known as hadrons.


 Leptons & Anti-leptons

There are also six flavours of leptons in three generations.

Again there is a corresponding anti-lepton table.

Negatively charged leptons can be represented by the symbol l- and positively charged ones by l+, the general symbol being l.

The general symbol for a neutrino is neutrino and that for an antineutrino is anti-neutrino.


Last modified Sat 22 December 2001 . View page history
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