Conveners
Parallel session 26: Electromagnetic probes I
- Ralf Rapp (TAMU)
Despite decades of theoretical and experimental achievements, a coherent picture of the evolution in colliding heavy ion systems is still missing, particularly in the non-perturbative regime. Since photons are penetrating probes, the combined information of direct photon yields at low transverse momenta ($p_T$) and their azimuthally asymmetric emission (flow) provides important constraints on...
In a heavy-ion collision, photons, which do not interact strongly, have the advantage of escaping unimpeded from their emission source. Consequently, photons can carry valuable information about the properties and dynamics of the hot QCD medium created in heavy-ion collisions. Particularly, the transverse momentum distribution of direct virtual photons emitted from the hot QCD medium exhibits...
Electromagnetic probes ($\gamma$, $\gamma*$) are an excellent probe to investigate strong-interaction matter under extreme conditions. Their penetrating nature not only enables e.g. temperature measurements unbiased by the collective expansion of the fireball, but also an insight to the microscopic structure of the matter under investigation. The HADES experiment has measured virtual photons...
The measurement of dielectron production is a fundamental piece of the puzzle in the understanding of the hot and dense matter produced in ultra-relativistic heavy-ion collisions. The dielectron spectrum provides information that penetrates the veil of final-state hadronic interactions and provides direct access to the early phases of the collision. However, the interpretation of the measured...
We present a newly developed hybrid hadronic transport + hydrodynamics geared towards heavy ion collisions (HICs) at low to intermediate beam energies, and report on the resulting excitation function of dileptons. In this range of energies, covered by the STAR Beam Energy Scan program and the future CBM experiment at FAIR, it is unclear how to best decribe the medium evolution. At which beam...
Transport coefficients play an important role in characterizing hot and dense nuclear matter, such as that created in ultra-relativistic heavy-ion collisions (URHIC). The electric conductivity can be accessed via the electromagnetic (EM) spectral function's low-energy transport peak, which can be measured via thermal dilepton emission. Several facilities including the Schwer-Ionen Synchrotron...
