Resolved photon and multi-component model for $\gamma^*$p and $\gamma^* \gamma^*$ total cross section

Abstract

We generalize our previous model for $\gamma^* p$ scattering to $\gamma \gamma$ scattering. Performing a new simultaneous fit to $\gamma^* p$ and $\gamma \gamma$ total cross section we find an optimal set of parameters to describe both processes. We propose new measures of factorization breaking for $\gamma^* \gamma^*$ collisions and present results for our new model.