The DIS cross-sections ratio $R={\sigma }_L/{\sigma }_T$ at small x from HERA data

Abstract

We extract the deep inelastic scattering cross-sections ratio $R={\sigma }_L/{\sigma }_T$ in the range $10^{-4}\le x\le 10^{-1}$ from $F_2$ HERA data using very simple relations based on perturbative QCD. The result depends on only one parameter $\delta$, being $x^{-\delta }$ the behavior of the parton densities at low $x$, which has been determined recently with a good accuracy by the H1 group.

Latex file (6 pages), 1 Postscript figure