Eur. Phys. J. C (2006) 45: 759-769
https://doi.org/10.1140/epjc/s2005-02451-2

Theoretical Physics

BFKL resummation effects in γ^*γ^* → ρρ

¹ CPHT, École Polytechnique, 91128, Palaiseau, France
² Lawrence Berkeley National Laboratory, CA 94720, Berkeley, USA
³ Sołtan Institute for Nuclear Studies, Hoża 69, 00-681, Warsaw, Poland
⁴ Université de Liége, B4000, Liége, Belgium
⁵ Université Paris-Sud, LPT, 91405, Orsay, France

^* e-mail: REnberg@lbl.gov

Received: 18 August 2005
Revised: 5 November 2005
Published online: 5 January 2006

Abstract

We calculate the leading order BFKL amplitude for the exclusive diffractive process 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.