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We study momentum dependence of static magnetic susceptibility $\chi(q)$ inparamagnetic phase of Heisenberg magnets and its relation to critical behaviorwithin nonlinear sigma model (NLSM) at arbitrary dimension $2<d<4$. In thefirst order of $1/N$ expansion, where $N$ is the number of spin components, wefind $\chi(q)\propto[q^{2}+\xi^{-2}(1+f(q\xi ))]^{-1+\eta /2}$, where $\xi $ isthe correlation length, $q$ is the momentum, measured from magnetic wavevector, the universal scaling function $f(x)$ describes deviation from thestandard Landau-Ginzburg momentum dependence. In agreement with previousstudies at large $x$ we find $f(x\gg 1)\simeq (2B_{4}/N)x^{4-d}$; the absolutevalue of the coefficient $B_4$ increases with $d$ at $d>5/2$. Using NLSM, weobtain the contribution of the"anomalous" term $\xi^{-2}f(q\xi )$ to thecritical exponent $\nu $, comparing it to the contribution of thenon-analytical dependence, originating from the critical exponent $\eta $ (theobtained critical exponents $\nu $ and $\eta $ agree with previous studies). Inthe range $3\leq d<4$ we find that the former contribution dominates, and fullydetermines $1/N$ correction to the critical exponent $\nu $ in the limit$d\rightarrow 4.$

The non-analytic momentum dependence of spin susceptibility of Heisenberg magnets in paramagnetic phase and its effect on critical exponents