Prediction for unintegrated parton distributions

TL;DR

This paper predicts unintegrated parton distributions in protons and nuclei using a modified DGLAP equation with shadowing corrections, highlighting nuclear shadowing effects and the influence of valence-like inputs on gluon suppression.

Contribution

It introduces a modified DGLAP framework that includes energy-momentum conserving shadowing corrections for unintegrated parton distributions.

Findings

Nuclear shadowing effects are significant but not at saturation levels.

Suppression of gluon distribution at low transverse momentum may stem from valence-like inputs.

Shadowing corrections are incorporated with exact energy-momentum conservation.

Abstract

Unintegrated parton distributions in the proton and nucleus are predicted by a modified DGLAP equation incorporating the shadowing corrections, which include exact energy-momentum conservation in each splitting and fusion vertices. We find that the nuclear shadowing effects are obvious, although they are far from the saturation limit. On the other hand, we point out that the suppression of the unintegrated gluon distribution toward lower $k_t^2$ may arise from the valence-like input rather than the saturation effects.