COUPLED-CLUSTER METHOD IN HAMILTONIAN LATTICE FIELD THEORY

The coupled cluster or exp(S) form of the eigenvalue problem for a lat tice Hamiltonian QCD (without quarks) is investigated. A new construct ion prescription is given for the calculation of the relevant coupled cluster matrix elements with respect to an orthogonal and independent loop space basis. The method avoids the explicit introduction of gauge roup coupling coefficients by mapping the eigenvalue problem onto a s uitable set of character functions, which allows a simplified procedur e. Using appropriate group theoretical methods. we show that it is pos sible to set up the eigenvalue problem for eigenstates having arbitrar y lattice momentum and lattice angular momentum.