S. Caracciolo et al., Operator product expansion on the lattice: a numerical test in the two-dimensional non-linear sigma-model, J HIGH EN P, 2000(9), 2000, pp. NIL_915-NIL_969
We consider the short-distance behaviour of the product of the Noether O(N)
currents in the lattice nonlinear sigma -model. We compare the numerical r
esults with the predictions of the operator product expansion, using one-lo
op perturbative renormalization-group improved Wilson coefficients. We find
that, even on quite small lattices (m alpha approximate to 1/6), the pertu
rbative operator product expansion describes that data with an error of 5-1
0% in a large window 2 alpha. less than or similar to x less than or simila
r to m(-1). We present a detailed discussion of the possible systematic err
ors.