The Light-Front Coupled-Cluster Method Applied to $${\phi_{1+1}^4}$$ ϕ 1 + 1 4 Theory

Abstract

We use the light-front coupled-cluster (LFCC) method to compute the odd-parity massive eigenstate of \({\phi_{1+1}^4}\) theory. A standard Fock-space truncation of the eigenstate yields a finite set of linear equations for a finite number of wave functions. The LFCC method replaces Fock-space truncation with a more sophisticated truncation; the eigenvalue problem is reduced to a finite set of nonlinear equations without any restriction on Fock space, but with restrictions on the Fock wave functions. We compare our results with those obtained with a Fock-space truncation.