Speaker
Description
In high temperature and/or density plasmas, perturbative calculations typically assume massless plasma constituents. We consider small masses ($m \ll T$ or $m \ll \mu$) and compute mass corrections ($\sim m^2/T^2$ or $\sim m^2/\mu^2$) for the photon polarization tensor in a QED plasma at high temperature $T$ or chemical potential $\mu$.
To this aim, we employ EFT techniques, the so called On-Shell Effective Field Theory (OSEFT) for fermions.
Next, we examine the collisional energy loss experienced by a high-energy fermion as it traverses a hot QED plasma with temperature T, taking into consideration the aforementioned mass corrections. To effectively separate between collisions involving hard and soft transfer momentum, we demonstrate the utilization of Dimensional regularization. Additionally, we evaluate the significance of these corrections in a QCD plasma.
Finally, we have recently developed an EFT aimed for the description of highly energetic electromagnetic fields, the OSEFT for photons. The high energy limit describes the eikonal semi-classical approximation, and our treatment allows to compute quantum corrections to that, organized as an energy expansion. We will comment on the EFT techniques used to build the theory and some of its properties and applications.
