Speaker
Charlotte Hellmann
(Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen)
Description
The Sommerfeld enhancement effect has been studied in dark matter
annihilations in the present universe as a means to boost the dark
matter annihilation cross section. It has also been applied to relic
abundance calculations in the MSSM with the neutralino LSP as dark
matter candidate, where however the enhancement effect is milder
due to the larger relative velocities of the annihilating particles.
In this talk we consider the Sommerfeld effect on the neutralino
dark matter relic abundance in the MSSM using non-relativistic
effective field theory techniques. Compared to previous results,
we compute analytically coannihilations with nearly mass degenerate
particles of the neutralino/chargino sector including the off-diagonal
annihilation amplitudes through order-v^2 in the velocity expansion;
include separately the S-wave and P-wave as well as order v^2 S-Wave
enhancements. We account for all spin-independent and spin-dependent
potential interactions through lighter Higgs and gauge boson exchange
as well as all accessible annihilation rates into Standard model and
Higgs final states.
We discuss numerical results for realistic MSSM scenarios with Wino- or
Higgsino-like neutralino LSP.