Scanning the BFKL pomeron in elastic production of vector mesons at HERA

Elastic production of vector mesons $\gamma^{*} N\to V N$ is the pomeron-exchange dominated diffractive reaction with much potential of probing the BFKL pomeron. The BFKL pomeron can conveniently be described in terms of the dipole cross section which is a solution of the generalized BFKL equation. In this paper we discuss, how the energy and $Q^{2}$ dependence of elastic production of vector mesons at HERA will allow scanning the dipole cross section as a function of dipole size $r$. We show that determinaton of the intercept of the BFKL pomeron requires measuring the $\rho^{0}$ and $J/\Psi$ production at $Q^{2} \sim (100-200)GeV^2$ and/or the quasireal photoproduction of the $\Upsilon$. We present predictions for the effective intercept in the kinematic range of the forthcoming HERA experiments, which can shed much light on the nonperturbative component of the pomeron.