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

We generalize our previous model for ${\gamma }^{\ast }p$ scattering to $\gamma \gamma$scattering\mathrm{.}Performinganewsimultaneousfitto$\gamma^* p$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 ${\gamma }^{\ast }{\gamma }^{\ast }$ collisions and present results for our new model.