Impact of SUSY-QCD corrections on neutralino-stop co-annihilation and the neutralino relic density

TL;DR

This paper calculates supersymmetric QCD corrections to neutralino-stop co-annihilation in the MSSM, showing significant effects on relic density predictions that surpass current experimental uncertainties.

Contribution

It provides the first full O(alpha_s) SUSY-QCD correction calculation for neutralino-stop co-annihilation, highlighting its importance for accurate relic density estimates.

Findings

Corrections significantly alter co-annihilation cross sections.

Impact on relic density exceeds current experimental uncertainties.

Relevance in phenomenological MSSM scenarios with a 126 GeV Higgs.

Abstract

We have calculated the full O(alpha_s) supersymmetric QCD corrections to neutralino-stop co-annihilation into electroweak vector and Higgs bosons within the Minimal Supersymmetric Standard Model (MSSM). We performed a parameter study within the phenomenological MSSM and demonstrated that the studied co-annihilation processes are phenomenologically relevant, especially in the context of a 126 GeV Higgs-like particle. By means of an example scenario we discuss the effect of the full next-to-leading order corrections on the co-annihilation cross section and show their impact on the predicted neutralino relic density. We demonstrate that the impact of these corrections on the cosmologically preferred region of parameter space is larger than the current experimental uncertainty of WMAP data.