Recent results from HADES on electron pair production in relativistic heavy-ion collisions

TL;DR

This paper reports recent experimental results from the HADES spectrometer on electron pair production in elementary and heavy-ion collisions, aiming to understand dilepton emission mechanisms at moderate densities and temperatures.

Contribution

It provides new experimental data on electron pair production in elementary collisions, helping clarify the origin of excess dileptons observed in heavy-ion collisions.

Findings

Observation of electron pair production in elementary collisions.

Insights into the origin of excess dileptons in heavy-ion collisions.

Comparison with previous DLS and HADES measurements.

Abstract

Systematic investigations of dilepton production are performed at the SIS accelerator of GSI with the HADES spectrometer. The goal of this program is a detailed understanding of di-electron emission from hadronic systems at moderate temperatures and densities. New results obtained in HADES experiments focussing on electron pair production in elementary collisions are reported here. They pave the way to a better understanding of the origin of the so-called excess pairs earlier on observed in heavy-ion collisions by the DLS collaboration and lately confirmed in two measurements of the HADES collaboration using C+C and Ar+KCl collisions. Results of these studies are discussed.