The longitudinal structure function of the proton for small x

Abstract

A comparison of the H1 data on the longitudinal structure function, $F_L$, at small $x$ with the predictions from the generalized vector dominance / color dipole picture (GVD/CDP) is presented. Using the set of parameters previously determined in the fits to the total cross section, ${\sigma }_{{\gamma }^{\ast }p}$, we find good agreement with the data for $F_L$. Scaling in $\eta =(Q^2+m_0^2)/{\Lambda }^2(W^2)$ is discussed in detail for the longitudinal and transverse photoabsorption cross sections.

9 pages, Latex 2e using epsfig, 3 figures