Direct photon emission in heavy ion collisions from microscopic transport theory and fluid dynamics : XLVIII International Winter Meeting on Nuclear Physics, BORMIO2010, January 25 - 29, 2010, Bormio, Italy
- Direct photon emission in heavy-ion collisions is calculated within a relativistic micro+macro
hybrid model and compared to the microscopic transport model UrQMD. In the hybrid approach,
the high-density part of the collision is calculated by an ideal 3+1-dimensional hydrodynamic
calculation, while the early (pre-equilibrium-) and late (rescattering-) phase are calculated with
the transport model. Different scenarios of the transition from the macroscopic description to
the transport model description and their effects are studied. The calculations are compared to
measurements by the WA98-collaboration and predictions for the future CBM-experiment are
made.