The DLLA limit of BFKL in the Dipole Picture

Abstract

In this work we obtain the DLLA limit of BFKL in the dipole picture and compare it with HERA data. We demonstrate that in leading-logarithmic- approximation, where ${\alpha }_s$ is fixed, a transition between the BFKL dynamics and the DLLA limit can be obtained in the region of $Q^2\approx 150Ge{V}^2$. We compare this result with the DLLA predictions obtained with ${\alpha }_s$ running. In this case a transition is obtained at low $Q^2$ $(\le 5Ge{V}^2)$. This demonstrates the importance of the next-to-leading order corrections to the BFKL dynamics. Our conclusion is that the $F_2$ structure function is not the best observable for the determination of the dynamics, since there is great freedom in the choice of the parameters used in both BFKL and DLLA predictions.

Comments: 14 pages, 2 figures, Accepted for publication in Phys. Lett. B