Quark-composites approach to QCD: The nucleons - art. no. 074008

We present a new perturbative approach to QCD based on the use of quark com posites with hadronic quantum numbers as fundamental variables. We apply it to the case of the nucleons by performing a nonlinear change of variables in the Berezin integral which defines the partition function of QCD. The nu cleon composites are thereby assumed as new integration variables. We evalu ate the Jacobian and certain transformation functions which appear in the c hange of variables. We show that the free action of the nucleon composites is the Dirac action, and we evaluate the first perturbative contributions t o their electroweak effective action, which turn out to be a pure renormali zation. Our expansion is compatible with a perturbative as well as nonpertu rbative regime of the gluons and it has the characteristic feature that the confinement of the quarks is built in. [S0556-2821(99)02317-6].