Analysis of quarkonium polarization in proton-proton (p-p) collisions at LHC using PYTHIA model

TL;DR

This study uses PYTHIA8 Monte Carlo simulations to analyze quarkonium polarization in proton-proton collisions at LHC energies, incorporating detector effects and comparing results with ALICE measurements.

Contribution

It provides a detailed simulation-based analysis of quarkonium polarization, including detector effects, at different energies and rapidities, aligning with experimental data.

Findings

Simulation results agree with ALICE measurements within uncertainties.

Detector effects significantly influence the measured polarization parameters.

The study offers insights into polarization behavior at different energies and rapidities.

Abstract

The measurement of polarization serves as an important probe to investigate the production mechanism of quarkonia, the bound state of heavy quark anti-quark (charm or bottom) pairs, in hadronic collisions. In experimental invesigations, the polarization is usually measured by analyzing the anisotropies in the angular distribution of the muons originating from the decay of the quarkonium state. In the present article, we study the charmonia ($J/\psi$) and bottomonia ($\Upsilon(1S)$) polarization at $\sqrt{s} =7 $ and 13 TeV in proton-proton(p-p) collisions at LHC using Monte Carlo (MC) event generator model PYTHIA8, which is based on perturbative QCD. The transverse momentum ($p_{T}$) differential distribution has been calculated at forward rapidity ($2.5 < y_{\mu\mu} < 4.0$) and the polarization parameters are estimated in Helicity and Collins-Sooper reference frames. In addition, to mimic realistic experimental conditions, we have incorporated, in PYTHIA simulations, effects like detector inefficiencies and muon momentum smearing. These contributions alter the polarization parameters, introducing an artificial degree of polarization, if not properly corrected for. The simulation results have been compared with the recent ALICE measurements for quarkonia polarization in p-p collisions at LHC energy regime.