2019/12/11 by S. Kundu, Kundu, Sourav, B. Mohanty +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1912.05176
openalex publication_date 2019/12/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Color reconnection (CR) mechanism in PYTHIA model has been reported to be essential to describe the flow-like collective effect observed in high multiplicity p+p and p+Pb collisions. In this work, we test this mechanism towards explaining the Forward-Backward multiplicity correlation (b_\mathrm cor) measurements in p+p collisions at the LHC energies. Out of the three different CR schemes implemented in PYTHIA, (a) MPI based CR (default mechanism), (b) QCD based CR and (c) Gluon moved CR, we found that the QCD based CR scheme describes relatively better the ALICE measurements of b_\mathrm cor in p+p collisions at √(\mathrm s) = 0.9 and 7 TeV. In addition, we have tuned the parameters of the default CR mechanism in PYTHIA to describe simultaneously the measured charged particle multiplicity pseudo-rapidity (η) distribution and b_\mathrm cor. We found that an average number of multipartonic interactions (⟨ N_\mathrm MPI ⟩) between 2.5 to 3 and CR range between 0.9 to 2.5 best describes the experimental data. Finally, we have presented a study using PYTHIA events for p+p collisions at √(\mathrm s) = 7 TeV which shows that the strength of Forward-Backward mean transverse momentum correlation (b^⟨ pT⟩ ⟨ pT ⟩_\rm cor) is found to increase with CR in contrast to decrease of b_\rm cor values with CR effect. Hence, simultaneously studying the b^⟨ pT⟩ ⟨ pT ⟩_\rm cor and b_\mathrm \rm cor in the experiments will help in establishing the arguments either in favour or in disfavour of CR effect in the measurements.
PYTHIA8