DIQUARKS IN QCD WITH A LINEAR CONFINEMENT POTENTIAL

We explore the diquark-quark picture of the octet and the decuplet of low-lying baryons in QCD with a linear confinement potential. The mass spectra of scalar, pseudoscalar, vector and axial-vector diquarks, tr ansforming like (($) over tilde ($) under bar 3(f),($) over tilde ($) under bar 3(c))) and (6(f),($) over tilde ($) under bar 3(c)), are ana lysed. For scalar, pseudoscalar and vector diquarks we find bound stat es with masses M(s) similar or equal to M(p)=1.95 GeV, and M(V)=2.40 G eV, whereas for axial-vector diquarks no bound states exist. We conclu de that low-lying baryons cannot be described by the diquark-quark pic ture. Our results confirm the three-body structure of low-lying baryon s, and lead to an unambiguously fixed spinor structure of three-quark currents of low-lying baryons as proposed by Ioffe, Pascual and Tarrac h.