Forward-backward multiplicity and momentum correlations in $pp$ collisions at LHC energies

TL;DR

This study investigates forward-backward correlations in proton-proton collisions at LHC energies using EPOS3 simulations, comparing results with experimental data and highlighting the impact of hydrodynamical evolution on correlation strength.

Contribution

It provides a detailed analysis of FB correlation dependence on various parameters and demonstrates that EPOS3 with hydrodynamics better matches ATLAS data.

Findings

EPOS3 qualitatively reproduces correlation trends.

Hydrodynamical evolution improves quantitative agreement.

Correlation strength varies with pseudorapidity gap and energy.

Abstract

Charged-particle multiplicity and summed values of the transverse momentum ($p_{\rm T}$) have been utilized for estimating forward-backward (FB) correlation strength for EPOS3 simulated proton-proton ($pp$) events with and without hydrodynamical evolution of particles at center-of-mass energies $\sqrt{s}$ = 0.9, 2.76, and 7 TeV for different pseudorapidity window width ($\delta\eta$) and gap ($\eta_{gap}$) between the FB windows. We have studied the variation of FB correlation strength with $\eta_{gap}$, $\delta\eta$, $\sqrt{s}$, $p_{\rm T}$ cuts and multiplicity classes. Results are compared with the corresponding ALICE and ATLAS data. EPOS3 model qualitatively reproduces the overall variation of correlation strength of the LHC data. However, quantitative agreement is better for $pp$ events, generated using EPOS3 with hydrodynamical evolution of particles, with ATLAS data.