Speaker
Mr
Francesco Dighera
(Technische Universitaet Muenchen)
Description
There is an increasing interest in accurate dark matter relic density
predictions, which requires next-to-leading order (NLO) calculations.
The method applied up to now uses zero-temperature NLO calculations
of annihilation cross sections in the standard Boltzmann equation
for freeze-out, and is conceptually problematic, since it ignores the
finite-temperature infrared (IR) divergences from soft and collinear
radiation and virtual effects. I address this problem systematically by
starting from non-equilibrium quantum field theory, and demonstrate on a
realistic model that soft and collinear temperature-dependent divergences
cancel in the collision term. This analysis provides justification for the
use of the freeze-out equation in its conventional form
and determines the leading finite-temperature
correction to the annihilation cross section. This turns out to
have a remarkably simple structure.
Authors
Dr
Andrzej Hryczuk
(Technische Universitaet Muenchen)
Mr
Francesco Dighera
(Technische Universitaet Muenchen)
Prof.
Martin Beneke
(Technische Universitaet Muenchen)
