Diquark correlations in the proton

The colour-magnetic interaction of quantum chromodynamics with a smearing function found from the fit to the ρ - π splitting is strong enough to support a bound state of a singlet q q-bar pair. We examine the possibility of this interaction leading to short-range quark-quark correlations in light baryons there - by providing the dynamical mechanism for a quark-diquark picture of the proton. In particular, we show that the correlation function of a singlet diquark in the proton is strongly enhanced at the origin (compared to that for the triplet diquark) with the correlation radius r0, a typical cut-off radius in the spin interaction. The Fourier transform of the correlation function, which is related to the dependence on the momentum transfer of the structure functions in inclusive electron-proton scattering, may provide quite fundamental information on the diquark structure of the proton. (author)