Study of charged-particle multiplicity fluctuations in pp collisions with Monte Carlo event generators at the LHC

TL;DR

This study uses Monte Carlo simulations with PYTHIA and HERWIG to analyze charged-particle multiplicity fluctuations in proton-proton collisions at various LHC energies, focusing on high-density events in narrow pseudorapidity windows.

Contribution

It provides a detailed simulation-based analysis of charged-particle density fluctuations in pp collisions at LHC energies, aiding future searches for anomalous high-density fluctuations.

Findings

Charged-particle density increases with event multiplicity.

Maximum density correlates with pseudorapidity window size.

Simulations prepare for future high-density fluctuation searches.

Abstract

Proton-Proton ($pp$) collisions at the Large Hadron Collider (LHC) are simulated in order to study events with a high local density of charged particles produced in narrow pseudorapidty windows of $\Delta\eta$ = 0.1, 0.2, and 0.5. The $pp$ collisions are generated at center of mass energies of $\sqrt{s} = 2.36$, $7$, $8$, and $13$ TeV, i.e. the energies at which the LHC has operated so far, using PYTHIA and HERWIG event generators. We have also studied the average of the maximum charged-particle density versus the event multiplicity for all events, using the different pseudorapidity windows. This study prepares for the multi-particle production background expected in a future search for anomalous high-density multiplicity fluctuations using the LHC data.