Theoretical Physics Colloquium by Prof. Jean-Francois Paquet from Vanderbilt University.
This presentation was held live on February 1, 2023 as part of the theoretical physics colloquium series hosted by Prof. Igor Shovkovy at the Arizona State University. The series features high-quality interactive presentations on current advances in theoretical physics by active researchers in the field of theoretical physics.
Abstract for this presentation:
The energy spectrum of photons is understood well in ultrarelativistic collisions of protons or of nuclei, as long as the photons' energy reaches the multiple GeV range. For single-GeV-energy photons, however, considerable differences appear between the collisions of protons and of nuclei. In the heavy ion case, the production of these lower-energy photons appears to be dominated by electromagnetic radiation from the plasma of deconfined nuclear matter produced in the collisions. I will discuss the status of theoretical calculations of the photon energy spectrum in proton-proton and heavy-ion collisions, reviewing the different production mechanisms, current agreement with experimental data, as well as recent developments. I will additionally discuss the momentum anisotropy (v2, v3) of photons.