Related papers: Direct Photons and Photon-Hadron Correlations at P…
In central collisions at relativistic heavy ion colliders like the Relativistic Heavy Ion Collider RHIC/Brookhaven and the Large Hadron Collider LHC (in its heavy ion mode) at CERN/Geneva, one aims at detecting a new form of hadronic matter…
Direct photon production in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV has been measured. The result is compared to several theoretical calculations, and found that it is not inconsistent with ones including thermal radiation from QGP or…
The last decades of high energy physics revealed, that in ultra-relativistic ion-ion collisions, a strongly interacting quark gluon plasma (sQGP) is created. Varying the collision energy allows for the investigation of the phase diagram of…
Quarkonia provide a sensitive probe of the properties of the hot dense medium created in high energy heavy ion collisions. Hard scattering processes result in the production of heavy quark pairs that interact with the collision medium…
The observed large elliptic flow ($v_2$) of direct photons in relativistic heavy ion collisions challenges us to explain. In this paper we consider only two sources of direct photons, prompt photons and thermal photons. Prompt photons are…
At the Relativistic Heavy Ion Collider (RHIC) collisions of heavy ions at nucleon-nucleon energies of 200 GeV appear to have created a new form of matter thought to be a deconfined state of the partons that ordinarily are bound in…
Theoretical and experimental studies of hot and/or dense matter, such as is created in high-energy heavy-ion collisions, and encountered in compact objects in astrophysics, constitute one of the most active frontiers in nuclear physics. In…
The productions of real photons from quark gluon plasma and hot hadronic matter formed after the nucleus - nucleus collisions at ultra-relativistic energies are discussed. The effects of the spectral shift of the hadrons at finite…
A measurement of direct photon production in Pb+Pb collisions at 158 AGeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons in central collisions is extracted as a function of transverse momentum in the…
A measurement of direct photon production in Pb+Pb collisions at 158 AGeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons in central collisions is extracted as a function of transverse momentum in the…
Collisions of atomic nuclei at relativistic velocities allow to recreate the conditions encountered in neutron stars or in the early universe micro-seconds after the Big Bang. These reactions are performed in today's largest accelerator…
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…
Heavy quarks are good probes of the hot and dense medium created in relativistic heavy ion collisions since they are mainly generated early in the collision and interact with the medium in all collision stages. In addition, heavy flavor…
Within the finite-time-path out-of-equilibrium quantum field theory (QFT), we calculate direct photon emission from early stages of heavy ion collisions, from a narrow window, in which uncertainty relations are still important and they…
Prompt photons are created in the early stages of heavy ion collisions and traverse the QGP medium without any interaction. Therefore, photon-triggered jets can be used to study the jet quenching in the QGP medium. In this work,…
A review on experimental results for direct photon production in heavy ion reactions is given. A brief survey of early direct photon limits from SPS experiments is presented. The first measurement of direct photons in heavy ion reactions…
Direct photon spectra measured at small $p_T$ in p+p, d+Au and Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV are presented. Several measurement techniques including statistical subtraction, tagging, and internal and external conversion were…
Prompt photons produced in a hard reaction are not accompanied with any final state interaction, either energy loss or absorption. Therefore, besides the Cronin enhancement at medium transverse momenta pT and small isotopic corrections at…
Estimations of prompt photon production at FAIR (Facility for Antiproton and Ion Research) energies using the extrapolation of existing data are presented. About $10^{-4}$ prompt $\gamma$ with $p_{t}>$2 GeV/c per Au+Au central event at 25…
Anisotropic flow can offer significant information of evolution dynamics in heavy-ion collisions. A systematic study of the directed flow $v_1$ and elliptic flow $v_2$ of hard photons and free nucleons is performed for $^{40}$Ca+$^{40}$Ca…