coupling ${^Q T_{(0)}} ( \omega, x ) = \omega /
( x \omega - 1 )$.

On the other hand the conformal OPE [@FGG73; @Mue97] for the product of two electromagnetic currents sandwiched between the hadronic states, in the kinematics appropriate to the process in question, gives the following prediction: $$\label{COPE}
{\cal F}^{\mit\Gamma} ( \omega, \zeta ) =
\sum_{i} \sum_{j = 0}^{\infty}
{^iC_j^{\mit\Gamma}} (\alpha_s,Q^2/\mu^2) \
\omega^{j + 1}
{_2F_1} \left( \left.
{
1 + j + {^i\gamma^{\mit\Gamma}_j},\
2 + j + {^i\gamma^{\mit\Gamma}_j}
\atop
4 + 2j + 2\, {^i\gamma^{\mit\Gamma}_j}
}
\right| \omega \zeta \right)
\langle h' | {^i \widetilde {\cal O}}^{\mit\Gamma}_{jj} | h \rangle .$$ Here ${_2F_1}$ is confluent hypergeometric function [@BE53_1], the index $i$ sums up the eigenvectors ${^i\widetilde {\cal O}^{\mit\Gamma}}_{jj}$ of the singlet channel, which possess the diagonal anomalous dimensions ${^i\gamma^{\mit\Gamma}_j}$, and ${^iC_j^{\mit\Gamma}}$ is the Wilson coefficient of the forward scattering. We have the convention that in the interacting theory the scale dimension is shifted by the amount $2{^i\gamma^{\mit\Gamma}_j}$ compared to canonical one: $d_j = d_j^{\rm can} + 2{^i\gamma^{\mit\Gamma}_j}$. In Eq. (\[COPE\]) $\mu^2$ is a renormalization scale, while we have put the factorization scale $\mu^2_F$ equal to $Q^2$. Notice that for practical purposes ${\overline{\rm MS}}$ schemes will be 