Exploring the Effects of Color Reconnection on Net-Charge Fluctuations in $pp$ Collisions at $\sqrt{s}=2.76 \text{ TeV}$ using PYTHIA Monash

Abstract

This work explores the effects of various color reconnection (CR) configurations on the net charge fluctuations of charged particles generated in $pp$ collisions at a center-of-mass energy of $\sqrt{s}$ = 2.76 TeV, simulated with the PYTHIA Monash using the variable $\nu_{(+,-,\text{dyn})}$. The results are compared with experimental data from ALICE, revealing that the current PYTHIA simulation settings overestimate the net charge fluctuations relative to the experimental observations. Furthermore, $\nu_{(+,-,\text{dyn})}$ exhibits a clear dependence on the MPICR range parameter, where increasing the range leads to more negative $\nu_{(+,-,\text{dyn})}$ values, suggesting the geometric extent of CR directly modulates the strength of local charge correlation. To ensure these effects are not a trivial consequence of particle density, a comparison with a retuned NoCR baseline at fixed multiplicity was performed. This analysis confirms that CR induces a genuine dynamical shift in fluctuations that persists independently of the average charged-particle density. The study also shows that the net charge and net pion channels display the strongest suppression in $\langle N_{\text{ch}} \rangle \nu_{(+-,\text{dyn})}$ compared to the net kaon and net proton channels. Overall, the study offers a useful benchmark against experimental results and sheds light on the underlying dynamics of the PYTHIA Monash.