On the nonperturbative calculation of hadron field correlators

An approximate method incorporating the 1/N/sub c/ expansion and the quasiclassical approximation is considered for the calculation of correlation functions for hadron field operators in QCD. On the basis of this method an effective two-dimensional action for the hadron correlators is proposed. Variation of the action leads to the Yang-Mills equations with dynamical boundary conditions that take into account the presence of quarks. The solution of these equations describes a bare relativistic string with quarks at its ends. It is shown that during its motion a string forms a surface that has a constant scalar curvature and is imbedded in four-dimensional Euclidean space. The contribution of the indicated field configuration to the correlator is in agreement with the law of areas and does not die out in the limit N/sub c/→∞