Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

TL;DR

This paper investigates angular and current-target particle correlations in deep inelastic scattering at HERA, comparing experimental data with theoretical predictions and models, revealing both consistencies and discrepancies across different regimes.

Contribution

It provides the first detailed analysis of angular and long-range correlations in deep inelastic ep scattering, testing QCD predictions and Monte Carlo models against experimental data.

Findings

Support for scaling behavior of angular correlations at high Q2

Observation of anti-correlations between current and target regions

Quantitative discrepancies between data and models at high Q2

Abstract

Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.