Gluon shadowing in the low x region probed by the LHC

Abstract

Starting from an unintegrated gluon distribution which satisfies a `unified' equation which embodies both BFKL and DGLAP behaviour, we compute the shadowing corrections to the integrated gluon in the small x domain that will be accessible at the LHC. The corrections are calculated via the Korchegov equation, which incorporates the leading ln(1/x) triple-Pomeron vertex, and are approximately resummed using a simple Pade technique. We find that the shadowing corrections to xg(x,Q^2) are rather small in the HERA domain, but lead to a factor of 2 suppression in the region x \sim 10^-6, Q^2 \sim 4 GeV^2 accessible to experiments at the LHC.

Figures (1)

• Figure 1: The effect of shadowing on the integrated gluon distribution $xg(x,Q^2)$, at $Q^2 = 4~ {\rm GeV}^2$ and $20~ {\rm GeV}^2$. The continuous line is simply the unshadowed $xg$ obtained from $f_L$KMS. The dashed and dotted lines show the result of shadowing with $R=4$ and $5\ {\rm GeV}^{-1}$ respectively, where the 'radius' $R$ is defined in (\ref{['eq:b15']}) in terms of the proton profile function, $S(b)$.