Update of the Three-fluid Hydrodynamics-based Event Simulator: light-nuclei production in heavy-ion collisions

TL;DR

This paper updates the THESEUS event generator to include light-nuclei production in heavy-ion collisions, achieving good data reproduction without extra parameters by integrating coalescence modeling within a three-fluid hydrodynamics framework.

Contribution

The main novelty is the extension of the 3FD-based event generator to simulate light-nuclei production alongside hadrons, with improved resonance tables and no additional tuning.

Findings

Successfully reproduces NA49 light nuclei data

Integrates light-nuclei production into 3FD framework

Achieves accurate results without extra parameters

Abstract

We present an update of the event generator based on the three-fluid dynamics (3FD), complemented by Ultra-relativistic Quantum Molecular Dynamics (UrQMD) for the late stage of the nuclear collision~-- the three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD final State interactions (THESEUS). Two modifications are introduced. The THESEUS table of hadronic resonances is made consistent with that of the underlying 3FD model. The main modification is that the generator is extended to simulate the light-nuclei production in relativistic heavy-ion collisions, on the equal basis with hadrons. These modifications are illustrated by applications to the description of available experimental data. The first run of the updated generator revealed a good reproduction of the NA49 data on the light nuclei. The reproduction is achieved without any extra parameters, while the coalescence approach in 3FD requires special tuning of the coalescence coefficients for each light nucleus separately.