Dilepton production in proton-induced reactions at SIS energies with the GiBUU transport model

Abstract

We present dilepton spectra from p+p, d+p and p+Nb reactions at SIS energies, which were simulated with the GiBUU transport model in a resonance model approach. These spectra are compared to the data published by the HADES and DLS collaborations. It is shown that the ρ spectral function includes non-trivial effects already in elementary reactions, due to production via baryon resonances, which can yield large contributions to the dilepton spectrum. Dilepton spectra from nuclear reactions in the energy range of the HADES experiment are thus found to be sensitive also to properties of nucleon resonances in the nuclear medium.PACS. PACS-key discribing text of that key -PACS-key discribing text of that key arXiv:1203.3557v3 [nucl-th]

Electromagnetic probes in heavy-ion collisions

“…The former provides a very satisfactory description of dielectron production in elementary reactions. Only at the lowest collision energies some discrepancies in comparison to the HADES data in np collisions (from a quasi-free scattering analysis in dp collisions) are found, which we trace back mostly to the difficulties to fully describe and implement the bremsstrahlung contributions within the transport-model approach [32]. The comparison of the model with the Ar+KCl data (right panel of Fig.…”

“…1 we compare the results from the GiBUU transport model [32,[40][41][42][43] with the data from 3.5 GeV pp and 1.76A GeV Ar+KCl collisions from the HADES collaboration [38,39]. The model implements an extension of the baryon-resonance model described in [19] into the GiBUU transport simulation.…”

HADES results in elementary reactions

“…This distortion of the ρ meson spectral function in NN collision has the same origin as the in-medium one. Therefore, these data offer a way to check the interpretation of in-medium data and in first place the results obtained by the HADES collaboration in the reaction p+Nb at 3.5 GeV [9,10].…”

Vector Meson Spectral Functions in a Coarse-Graining Approach

“…A completely different ansatz is used in transport models [14][15][16][17][18][19][20]. These approaches treat the dynamics microscopically and account for non-equilibrium, but the implementation of full medium effects, which were discussed above (i.e.…”