A systematic analysis of transverse momentum spectra of $J/\psi$ mesons in high energy collisions

TL;DR

This paper performs a comprehensive analysis of $J/ar{J}$ meson transverse momentum spectra across various high-energy collision systems and energies, using a convolution of modified Tsallis--Pareto functions to understand production mechanisms.

Contribution

It introduces a convolution model of two TP-like functions to fit $J/ar{J}$ spectra, revealing trends of physical parameters across different collision conditions.

Findings

Successful fitting of experimental data across multiple collision systems and energies.

Identification of parameter trends with centrality, rapidity, and energy.

Enhanced understanding of $J/\psi$ production mechanisms in high-energy collisions.

Abstract

We aggregate the transverse momentum spectra of $J/\psi$ mesons produced in high energy gold-gold (Au-Au), deuteron-gold ($d$-Au), lead-lead (Pb-Pb), proton-lead ($p$-Pb), and proton-(anti)proton ($p$-$p(\overline{p})$) collisions measured by several collaborations at the Relativistic Heavy Ion collider (RHIC), the Tevatron Proton-Antiproton Collider, and the Large Hadron Collider (LHC). The collision energy (the center-of-mass energy) gets involved in a large range from dozens of GeV to 13 TeV (the top LHC energy). We consider two participant or contributor partons, a charm quark and an anti-charm quark, in the production of $J/\psi$. The probability density of each quark is described by means of the modified Tsallis--Pareto-type function (the TP-like function) while considering that both quarks make suitable contributions to the $J/\psi$ transverse momentum spectrum. Therefore, the convolution of two TP-like functions is applied to represent the $J/\psi$ spectrum. We adopt the mentioned convolution function to fit the experimental data and find out the trends of the power exponent, effective temperature, and of the revised index with changing the centrality, rapidity, and collision energy. Beyond that, we capture the characteristic of $J/\psi$ spectrum, which is of great significance to better understand the production mechanism of $J/\psi$ in high energy collisions.