Sommerfeld enhancement effect in neutralino relic abundance calculations

We address the Sommerfeld enhancement effect in neutralino dark matter relic abundance calculations in the MSSM using non-relativistic effective field theory techniques. Our work includes an analytical calculation of all S- and P-Wave (co-)annihilation rates with nearly mass degenerate particles in the neutralino/chargino sector up to order v2 in the velocity expansion, where we especially account for off-diagonal annihilation reactions. All spin-dependent and spin-independent potential interactions through Higgs and gauge boson exchange are taken into account and annihilations into all accessible Higgs and standard model final states are considered. We present numerical results for selected realistic MSSM scenarios.