QCD Corrections to Electroweak Vector Boson Scattering at Small Scattering Angles

Abstract

We investigate the role of a certain class of QCD corrections to electroweak vector boson scattering at small scattering angles and large energies. These are present since, from the perturbative analysis, the vector bosons may dissociate into quark-antiquark pairs giving rise to colour dipoles interacting through gluon exchanges. After the computation of the vector boson impact factors, we present expressions for the lowest order QCD scattering amplitude and for the leading logarithmic BFKL amplitude. Particularly we discuss numerical results for the process $\gamma\gamma\to ZZ$. The QCD corrections to the cross section resulting from the interference with the electroweak ones are estimated and compared with the leading pure electroweak part. Corrections resulting from the leading log BFKL amplitude are of the order of few percent already at the $0.5 - 1$ TeV energy range.Comment: 21 pages,9 figures, discussion on the helicity-flip impact factors added, typos correcte