On the anomalous dimensions of the multiple pomeron exchanges

Abstract

High energy hard scattering in large $N_c$ limit can be described by the QCD dipole model. In this paper, single, double and triple BFKL pomeron exchange amplitudes are computed explicitly within the dipole model. Based on the calculation, the general formula ${\gamma }_0^{(k)\ast }={\chi }^{-1}(k\chi (1/2))$ which governs the anomalous dimension of $1\Rightarrow k$ amplitude is conjectured. As far as the unitarity problem is concerned, we find that the anomalous dimension $\gamma$ varies from graph to graph due to the DGLAP evolution. In the end, a comparison between this computation and reggeon field theory is provided.

Comments: 26 pages, 7 figures. A few changes are made in Appendix F