BFKL resummation effects in gamma* gamma* --> rho rho
  We calculate the leading order BFKL amplitude for the exclusive diffractive process \gamma*_L(Q1^2) \gamma*_L(Q2^2) \to \rho_L^0 \rho_L^0 in the forward direction, which can be studied in future high energy e^+e^- linear colliders. The resummation effects are very large compared to the fixed-order calculation. We also estimate the next-to-leading logarithmic corrections to the amplitude by using a specific resummation of higher order effects and find a substantial growth with energy, but smaller than in the leading logarithmic approximation. 
R. Enberg, B. Pire, L. Szymanowski, S. Wallon