Ridge Production in High-Multiplicity Hadronic Ultra-Peripheral Proton-Proton Collisions

TL;DR

This paper proposes that high-multiplicity hadronic ridges in proton-proton collisions originate from aligned gluonic flux tube interactions, predicting similar phenomena in photon-photon collisions and linking ridge formation to color confinement in QCD.

Contribution

It introduces a novel flux tube alignment model for ridge formation and predicts ridge production in photon-photon collisions at high energies.

Findings

High-multiplicity ridges are due to aligned gluonic flux tubes.

Ridge phenomena are predicted in photon-photon collisions at the LHC.

Azimuthal correlations can control and study ridge formation.

Abstract

An unexpected result at the RHIC and the LHC is the observation that high-multiplicity hadronic events in heavy-ion and proton-proton collisions are distributed as two "ridges", approximately flat in rapidity and opposite in azimuthal angle. We propose that the origin of these events is due to the inelastic collisions of aligned gluonic flux tubes that underly the color confinement of the quarks in each proton. We predict that high-multiplicity hadronic ridges will also be produced in the high energy photon-photon collisions accessible at the LHC in ultra-peripheral proton-proton collisions or at a high energy electron-positron collider. We also note the orientation of the flux tubes between the quark and antiquark of each high energy photon will be correlated with the plane of the scattered proton or lepton. Thus hadron production and ridge formation can be controlled in a novel way at the LHC by observing the azimuthal correlations of the scattering planes of the ultra-peripheral protons with the orientation of the produced ridges. Photon-photon collisions can thus illuminate the fundamental physics underlying the ridge effect and the physics of color confinement in QCD.