Dielectron production in C-12 _s16 C-12 collisions at 2-A-GeV with HADES

Abstract

We report on a measurement of electron pair production in (12)C_s16(12)C collisions at an incident energy of 2 GeV per nucleon with the HADES spectrometer. The measured pair production probabilities span over five orders of magnitude from the pi0 -Dalitz to the rho/omega invariant-mass region. Dalitz decays of pi0 and eta account for all the yield up to 0.15 GeV/c(2), but for only about 50% above this mass. The excess yield is in agreement with the former DLS result if one assumes that it scales w ith beam energy like pion production. A preliminary analysis of (12)C_s16(12)C collisions at an incident energy of 1 A GeV, measured with the HADES detector, supports this scenario.