The two-dimensional derivative-coupling model revisited

Abstract

Using the operator approach we reexamine the two-dimensional model describing a massive Fermi field interacting via derivative couplings with two massless Bose fields, one scalar and the other pseudoscalar. Performing a canonical transformation on the Bose field algebra, the Fermi field operator is written in terms of the Mandelstam soliton operator and the derivative-coupling (DC) model is mapped into the massive Thirring model with two vector-current–scalar-derivative interactions (Schroer–Thirring model). The DC model with massless fermions can be mapped into the massless Rothe–Stamatescu model with a Thirring interaction (massless Rothe–Stamatescu–Thirring model). Within the present approach the weak equivalence between the fermionic sector of the DC model and the massive Thirring model is exhibited compactly.