Longitudinal dynamics and particle production in relativistic nuclear collisions

TL;DR

This paper introduces a three-dimensional dynamical model for relativistic heavy-ion collisions that incorporates local energy-momentum conservation and baryon charge fluctuations, successfully describing various experimental data across multiple collision energies.

Contribution

The model uniquely integrates baryon charge fluctuations at string junctions and constrains parameters using p+p collision data, improving the description of particle distributions in heavy-ion collisions.

Findings

Accurately describes charged hadron and net proton rapidity distributions from 7.7 to 200 GeV.

Highlights the importance of baryon density fluctuations for net-proton distributions at 62.4 and 200 GeV.

Provides insights into early-time longitudinal dynamics through asymmetric collision systems.

Abstract

This work presents a three-dimensional dynamical initialization model for relativistic heavy-ion collisions, implementing local energy-momentum conservation and baryon charge fluctuations at string junctions. Constraining parameters using experimental data from p+p collisions at various collision energies, the model provides a very good description of the charged hadron and net proton rapidity distributions in Au+Au collisions from 7.7 to 200 GeV and Pb+Pb collisions at 8.77 and 17.3 GeV. We demonstrate the importance of fluctuations of baryon densities to string junctions for describing net-proton distributions at collision energies of 62.4 and 200 GeV. Including this improved baryon stopping description along with the requirement of strangeness neutrality also yields a good description of identified particle yields as functions of the collision energy above 7.7 GeV. We further study asymmetric p+Al and (p, d, $^3$He)+Au collisions at the top RHIC energy and p+Pb, Xe+Xe, and Pb+Pb collisions at LHC energies. We identify the produced particle rapidity distributions in asymmetric collision systems as particularly useful for constraining models of the early-time longitudinal dynamics.