Study of electromagnetic radiation from hot and dense medium formed in Au+Au collisions at √(s_NN) = 2.42 GeV

In heavy-ion collisions at energies 1-2 GeV per nucleon the medium is formed with baryon density a few times higher than normal nuclear matter density. The unique tool to study properties of such medium is electromagnetic radiation. HADES has investigated virtual photons produced in N+N, N+A, A+A and π+A reactions in this energy regime. The results from the largest system - Au+Au at √(s_NN) = 2.42 GeV - reveal nearly exponential low invariant mass spectra after subtracting properly contributions of first-chance NN collisions, and hadron decays at freeze-out. These findings suggest strong modification of vector meson spectral function, due to coupling to abundant baryon resonances, in accordance with significant drop of chiral condensate at such high densities. In this contribution, first results of differential data analysis are presented and compared to the available theory model calculations.