J/? and ?(2S) polarization in proton-proton collisions at energies available at the CERN Large Hadron Collider using PYTHIA8

Abstract

The production mechanisms of charmonium states in both hadronic and heavy-ion collisions hold great significance for investigating the hot and dense QCD matter. Studying charmonium polarization in ultrarelativistic collisions can also provide insights into the underlying production mechanisms. With this motivation, we explore the J/? and ?(2S) polarization in proton+proton collisions at s=7, 8, and 13 TeV using a pQCD-inspired Monte Carlo event generator called pythia8. This work considers reconstructed quarkonia through their dimuons decay channel in the ALICE forward rapidity acceptance range of 2.5<y??<4. Further, we calculate the polarization parameters ??, ??, ??? from the polar and azimuthal angular distributions of the dimuons in helicity and Collins-Soper frames. This study presents a comprehensive measurement of the polarization parameters as a function of transverse momentum, charged-particle multiplicity, and rapidity at the LHC energies. Our findings of charmonium polarization are in qualitative agreement with the corresponding experimental data. � 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.