Production and evolution path of dileptons at energies accessible to the HADES detector

Journal Article · Mon Jun 15 00:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.064908· OSTI ID:21293755

Schmidt, K; Santini, E; Vogel, S; Bleicher, M ^[1]; Sturm, C ^[2]; Stoecker, H ^[1]

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1. Institut fuer Theoretische Physik, Goethe-Universitaet, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany)
2. Institut fuer Kernphysik, Goethe-Universitaet, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany)

Dilepton production in intermediate energy nucleus-nucleus collisions as well as in elementary proton-proton reactions is analyzed within the ultrarelativistic quantum molecular dynamics transport model. For C+C collisions at 1A GeV and 2A GeV the resulting invariant mass spectra are compared to recent HADES data. We find that the experimental spectrum for C+C at 2A GeV is slightly overestimated by the theoretical calculations in the region around the vector meson peak but fairly described in the low mass region, where the data are satisfactorily saturated by the Dalitz decay of the {eta} meson and the {delta} resonance. At 1A GeV an underestimation of the experimental data is found, pointing that at lower energies the low-mass region is not fully saturated by standardly parametrized {delta} Dalitz decays alone. Furthermore, predictions for dilepton spectra for pp reactions at 1.25, 2.2, and 3.5 GeV and Ar+KCl reactions at 1.75A GeV are presented. The study is complemented by a detailed investigation of the role of absorption of the parent particles on the corresponding dilepton yields in the regime that has so far been probed by HADES.

• OSTI ID: 21293755
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 79, Issue 6; Other Information: DOI: 10.1103/PhysRevC.79.064908; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ABSORPTION
ATOM-ATOM COLLISIONS
ETA MESONS
FORECASTING
GEV RANGE 01-10
LEPTONS
MASS SPECTRA
MOLECULAR DYNAMICS METHOD
NUCLEAR DECAY
NUCLEI
PARTICLE PRODUCTION
POTASSIUM CHLORIDES
PROTON REACTIONS
PROTON-PROTON INTERACTIONS
PROTONS
RELATIVISTIC RANGE
TRANSPORT THEORY
VECTOR MESONS