Measurement of the azimuthal ordering of charged hadrons with the ATLAS detector

TL;DR

This study measures the azimuthal ordering of charged hadrons in proton-proton collisions at the LHC, revealing features consistent with a helix-like QCD string fragmentation not well modeled by conventional theories.

Contribution

It provides the first detailed spectral analysis of azimuthal correlations in charged hadron production at the LHC, suggesting a helix-like QCD string structure.

Findings

Correlations not well described by conventional models

Evidence supporting helix-like QCD string fragmentation

Observed features consistent across different energies

Abstract

This paper presents a measurement of the ordering of charged hadrons in the azimuthal angle relative to the beam axis in high-energy proton-proton collisions at the Large Hadron Collider (LHC). A spectral analysis of correlations between longitudinal and transverse components of the momentum of the charged hadrons, driven by the search for phenomena related to the structure of the QCD field, is performed. Data were recorded with the ATLAS detector at centre-of-mass energies of sqrt(s) = 900 GeV and sqrt(s) = 7 TeV. The correlations measured in a phase space region dominated by low-pT particles are not well described by conventional models of hadron production. The measured spectra show features consistent with the fragmentation of a QCD string represented by a helix-like ordered gluon chain.