Squark-, slepton-, and neutralino-chargino coannihilation effects in the low-energy effective minimal supersymmetric standard model

We calculate the neutralino relic density within the low-energy effective minimal supersymmetric extension of the standard model (effMSSM) taking into account slepton-neutralino, squark-neutralino and neutralino–chargino-neutralino coannihilation channels. By including squark (top squark and bottom squark) coannihilation channels we extend our comparative study to all allowed coannihilations and obtain the general result that all of them give sizable contributions to the reduction of the neutralino relic density. Because of these coannihilation processes some models (mostly with large neutralino masses) fall within the cosmologically interesting region for relic density, but other models drop out at this region. Nevertheless, the predictions for direct and indirect dark matter detection rates are not strongly affected by these coannihilation channels in the effMSSM.