CONFORMAL SYMMETRY AND THE SPECTRUM OF ANOMALOUS DIMENSIONS IN THE N-VECTOR MODEL IN 4-EPSILON DIMENSIONS

The subject of this paper is to study the critical N-vector model in 4 -epsilon dimensions in one-loop order. We analyse the spectrum of anom alous dimensions of composite operators with an arbitrary number of fi elds and gradients. For composite operators with three elementary fiel ds and gradients we work out the complete spectrum of anomalous dimens ions, thus extending the old solution of Wilson and Kogut for two fiel ds and gradients. In the general case we prove some properties of the spectrum, in particular a lower limit 0 + O(epsilon2). Thus one-loop c ontributions generally improve the stability of the nontrivial fixed p oint in contrast to some 2 + epsilon expansions. Furthermore we explic itly find conformal invariance at the nontrivial fixed point.