Event patterns extracted from transverse momentum and rapidity spectra of Z bosons and quarkonium states produced in pp and Pb-Pb collisions at LHC

TL;DR

This paper models the transverse momentum and rapidity spectra of Z bosons and quarkonium states in pp and Pb-Pb collisions at LHC using hybrid distributions, and visualizes the resulting event patterns in multi-dimensional space.

Contribution

It introduces a unified hybrid modeling approach for spectra and extracts event patterns from experimental data at LHC energies.

Findings

Model fits well with experimental data from LHC.

Event patterns reveal correlations in momentum and velocity space.

Hybrid distributions effectively describe particle spectra.

Abstract

Transverse momentum ($p_T$) and rapidity ($y$) spectra of $Z$ bosons and quarkonium states (some charmonium $c\bar c$ mesons such as $J/\psi$ and $\psi(2S)$, and some bottomonium $b\bar b$ mesons such as $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$) produced in proton-proton ($pp$) and lead-lead (Pb-Pb) collisions at the large hadron collider (LHC) are uniformly described by a hybrid model of two-component Erlang distribution for $p_T$ spectrum and two-component Gaussian distribution for $y$ spectrum. The former distribution results from a multisource thermal model, and the latter one results from the revised Landau hydrodynamic model. The modelling results are in agreement with the experimental data measured in $pp$ collisions at center-of-mass energies $\sqrt{s}=2.76$ and 7 TeV, and in Pb-Pb collisions at center-of-mass energy per nucleon pair $\sqrt{s_{NN}}=2.76$ TeV. Based on the parameter values extracted from $p_T$ and $y$ spectra, the event patterns (particle scatter plots) in two-dimensional $p_T$-$y$ space and in three-dimensional velocity space are obtained.