Probing the Pomeron structure using dijets and $\gamma$+jet events at the LHC

TL;DR

This paper investigates the structure of the Pomeron in proton-proton collisions at the LHC by analyzing dijet and photon-jet events, aiming to determine its quark and gluon content and test QCD models of diffraction.

Contribution

It proposes using specific diffractive measurements at the LHC to directly probe the Pomeron’s partonic structure and compare different QCD-based models of diffraction.

Findings

Potential to determine Pomeron quark and gluon contents

Photon-jet to di-jet cross section ratio as a QCD test

Comparison with soft color interaction predictions

Abstract

We consider hard diffractive events in proton-proton collisions at the LHC, in which both protons escape the collision intact. In such double Pomeron exchange processes, we propose to measure dijets and photon-jet final states, and we show that it has the potential to pin down the Pomeron quark and gluon contents, a crucial ingredient in the standard QCD description of hard diffraction. By comparing with predictions of the soft color interaction approach, we also show that more generally, the measurement of the photon-jet to di-jet cross section ratio can put stringent test on the QCD dynamics at play in diffractive processes in hadronic collisions.