Speaker
Description
Background electric fields might exist in the early stages of heavy-ion collisions. The response of the QCD medium to such fields is described by the electric susceptibility of QCD. In the past, various definitions were given for this observable that lead to different results at nonzero temperature. With the help of an exact fermion propagator in a homogenous electric background field at finite temperature and volume on the one hand and an improved perturbative result on the other, we elaborate on the origin of this disagreement. The equilibrium conditions for the system are discussed and the role of the thermodynamic ensemble used to describe the system is highlighted. Finally, we construct the electric susceptibility in a simplified hadron resonance gas model.
