BFKL resummation effects in gamma* gamma* --> rho rho
R. Enberg, B. Pire, L. Szymanowski, S. Wallon
TL;DR
The paper investigates high-energy QCD dynamics in the exclusive diffractive process γ*_L γ*_L → ρ_L ρ_L by computing the leading-order BFKL amplitude in the forward region and showing that resummation effects are significantly larger than fixed-order results. It also provides an estimate of next-to-leading logarithmic corrections through a specific higher-order resummation, observing substantial energy growth that is still smaller than the leading-logarithmic case. These results inform expectations for future e^+e^- collider measurements and highlight the importance of BFKL dynamics in vector-meson production at high energies.
Abstract
We calculate the leading order BFKL amplitude for the exclusive diffractive process γ*_L(Q1^2) γ*_L(Q2^2) \to ρ_L^0 ρ_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.