Electromagnetic Properties of Hadrons in the Static S U ₆ Model

Abstract

In the current thinking about strongly interacting particles one usually imagines that they are mixtures of certain bare particles e.g. the proton being partly a bare proton and partly a bare proton with a virtual p-wave pion around it. This picture was never very successful in explaining the electromagnetic properties of the baryons. The reason is that the well-explored outer part of the pion cloud does not contain much charge and magnetic moment and the core is rather complicated. It is the more remarkable that an alternative model where the baryons consist of three spin 1/2 particles called quarks is numerically very successful in predicting the electromagnetic properties. In this model one assumes that the quark interaction is spin- and unitary spin-independent and that there are no orbital contributions to the magnetic moments. The following table lists the quantum numbers of the three fundamental entities:

	Q	Y	N	T3	μ
p	2/3	1/3	1/3	1/2	2/3
n	-1/3	1/3	1/3	- 1/2	- 1/3
Λ	-1/3	- 2/3	1/3	0	- 1/3

µ is the magnetic moment measured in quark magnetons

Lecture given at the IV. Internationale Universitätswochen für Kernphysik, Schladming, 25 February–10 March 1965.