Medium modification of pion production in low energy Au+Au collisions

TL;DR

This study improves transport model predictions of charged pion yields in low-energy Au+Au collisions by refining the equation of state, cross sections, and nuclear potentials, aligning calculations more closely with experimental data.

Contribution

It introduces specific modifications to the GiBUU transport model to better match experimental pion yields in heavy-ion collisions.

Findings

Enhanced agreement with charged pion yields from Hades data.

Remaining discrepancy in neutral pion yields from dilepton measurements.

Demonstrated importance of in-medium effects and nuclear potentials.

Abstract

There is a major mismatch between the charged pion yields in Au+Au collisions at low energies calculated by various transport models and the experimental measured values from the Hades collaboration. In this work, reasonable improvements on the equation of state, in-medium modification of cross sections, and the influence of the nuclear potential for Delta resonances will be investigated in the framework of the GiBUU transport model. As a result, we demonstrate that theoretical calculations can indeed describe the charged pion yields measured by Hades for Au+Au collisions rather well, but that a mismatch then remains between calculations and data for the yields of neutral pions extracted from dileptons within the same experiment.