An introduction to the parton and hadron cascade model PACIAE 3.0

TL;DR

PACIAE 3.0 is a comprehensive parton and hadron cascade model that simulates nuclear collisions across energy ranges, incorporating new scattering processes, string interactions, and improved centrality-impact parameter mapping, successfully reproducing experimental data.

Contribution

This paper introduces PACIAE 3.0 with enhanced simulation frameworks, new scattering processes, and improved mapping relations, advancing the modeling of nuclear collisions at various energies.

Findings

Accurately reproduces experimental particle yields.

Models transverse momentum and rapidity distributions effectively.

Incorporates new partonic scattering and string interaction mechanisms.

Abstract

We introduce a parton and hadron cascade model PACIAE 3.0 based on PYTHIA 6.428 and the PACIAE 2.2 program series. The simulation framework of C-, B-, and A-loops are designed for the high energy ($\sqrt{s_{NN}}\geq 3$ GeV) and low energy ($\sqrt{s_{NN}}<3$ GeV) nuclear collisions, respectively, in PACIAE 3.0. In the C-loop simulation, the parton-parton inelastic scattering processes are added in the partonic rescattering process. The single string structure and multiple string interaction mechanism have been introduced investigating the strangeness enhancement in C- and B-loop. An improved mapping relation between the centrality percentage definition and the impact parameter definition is proposed responding the observation of $b_{max}\approx 20$ fm from ALICE, ATLAS, and CMS collaborations. We have extensively modified the phenomenological coalescence hadronization model. The PACIAE 3.0 model simulated results of particle yield, transverse momentum distribution, and rapidity distribution well reproduce, respectively, the experimental data measured at FOPI, E895, RHIC, and LHC energies.