Study of nuclear modification factors of (anti-)hadrons and light (anti-)nuclei in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV

TL;DR

This study investigates the nuclear modification factors of various hadrons and light nuclei in Pb-Pb collisions at 2.76 TeV, revealing similar suppression patterns for matter and antimatter and dependence on collision centrality and particle mass.

Contribution

It introduces a combined PACIAE and DCPC model approach to analyze the suppression of (anti-)hadrons and (anti-)nuclei in heavy-ion collisions, highlighting the similarity in their nuclear modification factors.

Findings

$R_{AA}$ of light (anti)nuclei is similar to that of hadrons.

Suppression at high-$p_T$ depends on collision centrality and particle mass.

Yield ratios of matter and antimatter are approximately equal across systems.

Abstract

The nuclear modification factors ($R_{AA}$) of $\pi^{\pm}, p(\bar p)$, and $d(\bar d)$ with $|y|<0.5, p_T<20.0$~GeV/c in peripheral (40-60\%) and central (0-5\%) Pb-Pb collisions at $\sqrt {s_{NN}}=2.76$ TeV have been studied using the parton and hadron cascade ({\footnotesize PACIAE}) model plus the dynamically constrained phase space coalescence ({\footnotesize DCPC}) model. It is found that the $R_{AA}$ of light (anti)nuclei ($d, \bar d$) is similar to that of hadrons ($\pi^\pm, p, \bar p$), and the $R_{AA}$ of antiparticles is the same as that of particles. The suppression of $R_{AA}$ at high-$p_T$ strongly depends on event centrality and mass of the particles, i.e., the central collision is more suppressed than the peripheral collision. Besides, the yield ratios and double ratios for different particle species in $pp$ and Pb-Pb collisions are discussed, respectively. It is observed that the yield ratios and double ratios of $d$ to $p$ and $p$ to $\pi$ are similar to those of their anti-particles in three different collision systems, suggesting that the suppressions of matter ($\pi^{+}, p, d$) and the corresponding antimatter ($\pi^{-},\bar{p},\bar{d}$) are around the same level.