we have the pleasure to invite you to the Particle Theory Seminar on Tuesday, March 21 at 12:15, which will be given by
Gergely Marko (University of Bielefeld)
"Electric susceptibility of the strongly interacting plasma"
"The response of strongly interacting matter to a background magnetic field is well understood by now thanks to first principles lattice QCD studies. The introduction of an electric field, however, suffers from a sign problem in Monte Carlo simulations, while also raising questions on the definiteness of a thermal equilibrium in general. As a first step towards lattice simulations for the electric susceptibility of QCD, we study the leading response of hot quark matter to external electric fields using a perturbative expansion in equilibrium thermal field theory. We discuss the specifics of the equilibrium state in the presence of the external electric field and calculate the susceptibility in a small field expansion. In comparison we also brush up the evaluation of the effective action in constant electric backgrounds using Schwinger's exact propagator obtained as one of the earliest results in the worldline formalism. We point out that the two approaches lead to different results, and discuss the origin of the difference."
The seminar will be in a hybrid mode, local people are invited to meet in the seminar room D-2-02.
Piotr Korcyl, Jacek Wosiek, Michał Praszałowicz