Exact expressions have been proposed for correlation functions of the large-N (planar) limit of the (1 + 1)-dimensional SU(N) × SU(N) principal chiral sigma model. These were obtained with the form-factor bootstrap. The short-distance form of the two-point function of the scaling field Φ(x), was found to be N −1 Tr Φ(0) † Φ(x) = C 2 ln 2 mx, where m is the mass gap, in agreement with the perturbative renormalization group. Here we point out that the universal coefficient C 2 , is proportional to the mean first-passage time of a Lévy flight in one dimension. This observation enables us to calculate C 2 = 1/16π.