Energy-Momentum Tensors and Scale Invariance in the Thirring Model

It is shown that in the Thirring model the Sugawara form of the energy-momentum tensor T_S^μν, is a more natural choice than the usual form in terms of canonical fields, T_C^μν, in the sense that ∫x_μT_S^μ0(x)dx¹ is the generator of scale transformations which leave the solution of the model invariant.