Structure functions of the 2d O(n) non-linear sigma models

Abstract We investigate structure functions in the 2-dimensional (asymptotically free) non-linear O ( n ) σ -models using the non-perturbative S-matrix bootstrap program. In particular, the exact small (Bjorken) x behavior is derived . Structure functions in the special case of the n = 3 model are accurately computed over the whole x range for − q 2 / M 2 10 5 , and some moments are compared with results from renormalized perturbation theory. Some results concerning the structure functions in the 1 / n approximation are also presented.