Neutralino annihilation processes in the minimal supergravity model

TL;DR

This paper analyzes neutralino annihilation processes in the minimal supergravity model, focusing on tree-level cross sections, dominant channels, and resonance effects due to heavy Higgs bosons, with implications for dark matter studies.

Contribution

It provides a comprehensive analysis of tree-level neutralino annihilation cross sections across mSUGRA parameter space, highlighting resonance effects and identifying dominant channels.

Findings

Resonances due to heavy Higgs bosons significantly increase cross sections.

Dominant annihilation channels vary across parameter space.

Cross sections mapped in m1/2-m0 planes for different tan(beta) and A0 values.

Abstract

We study all tree-level neutralino annihilation processes concerning energy-dependence at the mSUGRA benchmark point SPS1a using tree-level calculators MadGraph and CompHEP as well as FormCalc. We further investigate the total tree-level neutralino annihilation cross section by scanning over the mSUGRA parameters and identifying the dominant channels in every region. The results for the cross sections are presented in the m1/2-m0 planes for different values of tan(beta) and A0. We identify as well the resonances due to the exchange of the heavy Higgs bosons A and H in the s-channel of many neutralino annihilation processes, where the total cross section increases significantly if these Higgs bosons can be produced close to on-shell. Finally, we provide a few comments on the neutralino annihilation processes at loop-level.