MURRAY GELL-MANN (b.1929)

1964 – USA

‘Neutrons and protons are made up of particles called quarks. Like electrons, they cannot be subdivided further’

MURRAY GELL-MANN

The standard model of particle physics divides all elementary particles into three groups:

six types of leptons

electron, electron neutrino, muon, muon neutrino, tau and tau neutrino

six types of quarks

up, down, charm, strange, top and bottom    and

four types of bosons

   
Ordinary matter is made up of:

protons

each an up-up-down quark triplet

neutrons

each an up-down-down quark triplet    and

electrons

 

Gell-Mann predicted the existence of three quarks; up, down and strange. Other scientists predicted another three. Quarks cannot exist singly.

TIMELINE

STANDARD MODEL