The spin on the sea in a simple quark model

Abstract

We construct a simple quark model which reproduces hyperon beta decay, baryon magnetic moments and can accomodate the EMC result on the fraction of the spin of the nucleon carried by the spin of the quarks. Nucleons consist of three quarks in symmetric quark model configurations accompanied by a single QQ̄ pair with L= S=1 coupled to J PC =0 ++ or 1 ++. The QQ̄ pair can be SU(3) flavor symmetric or may contain no ss̄ pairs. In the latter case the model fits the data slightly better but requires an additional assumption that the QQ̄ pairs do not participate in β-decay.