Related papers: Spectral Red-Shift Versus Broadening from Photon a…
The intensive synchrotron radiation resulting from quarks interacting with the collective confining color field in relativistic heavy ion collisions is discussed. The spectrum of photons with large transverse momentum is calculated and…
Recently the HADES collaboration has published the invariant mass spectrum of $e^+e^-$ pairs, dN/dM$_{e^+e^-}$, produced in C+C collisions at 2 AGeV. Using electromagnetic probes, one hopes to get in this experiment information on hadron…
We discuss the latest theoretical results on direct photon and dilepton production from relativistic heavy-ion collisions. While the dilepton spectra at low invariant mass show in-medium effects like a collisional broadening of the vector…
We analyze the dilepton emission rates from the hot pion gas confined to a finite space-time volume. Two models of pion(+) pion(-) annihilation to dileptons are under consideration. The first model mimics an extreme influence of the dense…
We analyze dilepton emission from hot and dense matter using a hybrid approach based on the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport model with an intermediate hydrodynamic stage for the description of heavy-ion…
We evaluate currently available information on low-mass dilepton and direct-photon emission spectra measured in ultrarelativistic heavy-ion collisions. In the first part an attempt is made to develop a consistent picture of the in-medium…
We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic…
The notion of "hadronic freedom" is introduced based on the vector manifestation of hidden local symmetry and is used to suggest that the dileptons measured in relativistic heavy-ion collisions do not provide {\em direct} information on the…
An overview is given over recent results on in-medium properties of hadrons, obtained in experiments with photon, proton and deuteron beams at ANKE, CBELSA/TAPS, Crystal Ball, HADES, and BigRIPS. These experiments focus on identifying…
We study the net dielectron production rates from an ensemble of thermal mesons, using an effective Lagrangian to model their interaction. The coupling between the electromagnetic and the hadronic sectors is done through the vector meson…
Using clover improved Wilson fermions we calculate thermal vector meson correlation functions above the deconfinement phase transition of quenched QCD. At temperatures 1.5 Tc and 3Tc they are found to differ by less than 15% from that of a…
Through a consistent analysis of the terms neglected in going from the accurate expression to the one of Weizs\"{a}cker-Williams approximation (WWA), the validity of equivalent photon spectra is studied, and a modified photon flux of proton…
The standard (Bose-Einstein/Fermi-Dirac or Maxwell-Boltzmann) distribution from the relativistic ideal gas model is used to study the transverse momentum ($p_{T}$) spectra of identified charged hadrons ($\pi^-$, $\pi^+$, $K^-$, $K^+$, $\bar…
In this talk I first discuss predictions based on QCD sum rules and on hadronic models for the properties of vector mesons in the nuclear medium. I then describe possible experimental signatures and show detailed predictions for dilepton…
Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons) and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in…
The rho and omega meson self-energy at finite temperature and baryon density have been analysed for an exhaustive set of mesonic and baryonic loops in the real time formulation of thermal field theory. The large enhancement of spectral…
The enhancement in the dilepton spectrum observed in heavy-ion collisions for invariant electron-positron masses in the range 0.15 GeV/c$^2 < M_{e^+e^-} <$ 0.6 GeV/c$^2$ has recently been traced back to a corresponding enhancement in $pn$…
Thermal radiation of photons and dileptons from hadronic matter plays an essential role in understanding electromagnetic emission spectra in high-energy heavy-ion collisions. In particular, baryons and anti-baryons have been found to be…
Electro-magnetic probes such as dileptons and photons are strong probes to investigate the thermodynamical state of the early stages of collisions since they leave the system unscathed. The PHENIX experiment has measured both photons and…
The low $p_T$ direct photon production from a variety of the hadronic sources is studied within the microscopic HSD transport approach for p+C, p+Pb and Pb+Pb collisions at 160 A GeV. The direct photon emission from elementary hadronic…