Broadening and saturation effects in dijet azimuthal correlations in p-p and p-Pb collisions at [formula omitted

Andreas Van Hameren,Piotr Kotko,Krzysztof Kutak,Sebastian Sapeta

doi:10.1016/j.physletb.2019.06.055

Abstract

We demonstrate that the recent forward-forward dijet correlation data measured by the ATLAS collaboration for proton-proton and proton-lead collisions are consistent with the broadening effects due to both the gluon saturation and the resummation of large logarithms of a hard scale (the so-called Sudakov logarithms). We find that both effects are necessary to describe the experimental results.

Highlights

High energy collisions of protons and heavy nuclei at the Large Hadron Collider (LHC) provide a unique tool to probe dense systems of partons – quarks and gluons – bounded in a highly Lorentz-contracted, large nucleus
We demonstrate that the recent forward-forward dijet correlation data measured by the ATLAS collaboration for proton-proton and proton-lead collisions are consistent with the broadening effects due to both the gluon saturation and the resummation of large logarithms of a hard scale
Using the ITMD factorization together with Sudakov resummation, we provided good description of the shapes of the dijet correlations in p-p and p-Pb collisions, as recently measured by the ATLAS collaboration [3]

Summary

INTRODUCTION

High energy collisions of protons and heavy nuclei at the Large Hadron Collider (LHC) provide a unique tool to probe dense systems of partons – quarks and gluons – bounded in a highly Lorentz-contracted, large nucleus From this point of view, especially interesting are processes where well-defined jets of hadrons are produced in the forward direction with respect to the incoming proton. In the following work we show, for the first time, that the interplay of saturation effects and the resummation of the Sudakov logarithms is essential to describe the small-x jet data provided by the ATLAS experiment [3] To this end, we apply the ITMD formalism and the procedure of Sudakov resummation mimicking the parton-shower-like resummation proposed in [22]

THE FRAMEWORK

The quantities

RESULTS

SUMMARY