Scaling function for critical scattering

The zero-field, two-point correlation function of an n-vector system in d=4-ε dimensions is calculated to order ε2 for T>~Tc. The scaling function is obtained as a closed, cutoff-independent integral. As t=(T-Tc)Tc→0 at fixed wave vector q, the leading variation is E1n,d(q)t1-α+E2n,d(q)t, where α is the specific-heat exponent; thence the maximum in the scattering above Tc is located, in good agreement with high-T series-expansion estimates.