Low-x Physics

TL;DR

This paper reviews low-x physics, focusing on potential deviations from standard GLAP evolution in parton densities, and examines dipole models and saturation effects in light of experimental data.

Contribution

It provides a comprehensive review of low-x physics, analyzing the compatibility of dipole models and saturation with experimental observations, highlighting the lack of conclusive evidence for deviations from GLAP evolution.

Findings

No unambiguous evidence for deviations from standard GLAP evolution.

Dipole models qualitatively describe the data but are not uniquely supported.

Conventional explanations also fit the experimental data.

Abstract

Low-x physics is reviewed, with particular emphasis on searches for deviations from GLAP evolution of the parton densities. Although there are several intriguing indications, both in HERA and Tevatron data, as yet there is no unambiguous evidence for other than standard next-to-leading-order GLAP evolution. The framework of dipole models and saturation of parton densities is examined and confronted with the data. Although such models give a good qualitative description of the data, so do other, more conventional, explanations.