2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/214498We define a constituent quark within QCD. It is shown that the spin of such a quark and hence also the spin of the nucleon reduced due to $\bar{q}q$-pairs, in agreement with experiment. A solution to the spin problem is given.7 pagesHigh Energy Physics - Phenomenologytext