Quark Matter 2017

Low-mass electrons pairs from 1.23A GeV Au+Au Collisions with HADES

7 Feb 2017, 08:50

20m

Regency C

Oral Electromagnetic Probes Parallel Session 1.3: Electromagnetic Probes (I)

Speaker

Tetyana Galatyuk (TU Darmstadt / GSI)

Description

We present a first measurement of low-mass electron pairs for a heavy collision-system at SIS18/Bevalac energies. The data is analyzed in terms of excess radiation above a conventional cocktail of contributions from meson decay after thermal freeze-out. We observe a strong excess radiation which is remarkably well described assuming emission from a thermalized system. The high statistics data allows studying multi-differential distributions. The multiplicity of excess radiation in the mass window 300 to 700 MeV/$c^2$ rises with $A_{part}$ stronger than linear. To gain deeper understanding of the microscopic origin of the excess radiation we started to investigate di-electron radiation emitted from baryonic resonances produced off protons in pion-induced reactions. The data is in support of VMD in electromagnetic transition of excited baryons.

Presentation materials

2017_02_07_TetyanaGalatyuk_QM17_indico.pptx