${\gamma }^{\ast }{\gamma }^{\ast }$ total cross-section in the dipole picture of BFKL dynamics

Abstract

The total ${\gamma }^{\ast }{\gamma }^{\ast }$ cross-section is derived in the Leading Order QCD dipole picture of BFKL dynamics, and compared with the one from 2-gluon exchange. The Double Leading Logarithm approximation of the DGLAP cross-section is found to be small in the phase space studied. Cross sections are calculated for realistic data samples at the $e^{+}{e}^{-}$ collider LEP and a future high energy linear collider. Next to Leading order corrections to the BFKL evolution have been determined phenomenologically, and are found to give very large corrections to the BFKL cross-section, leading to a reduced sensitivity for observing BFKL.

Comments: 24 pages, 4 figures