2007/03/08 by Stephen P. Martin · 121 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Gaugino #Gluino #Grand Unified Theory #Higgs boson #Minimal Supersymmetric Standard Model #Neutralino #Particle physics #Particle physics theoretical and experimental studies #Physics #Quark #Superpartner #Supersymmetry #hep-ph
paper · pdf · doi:10.1103/physrevd.75.115005
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 75(11) (American Physical Society) · 18 pages
arxiv created 2007/03/08 · openalex publication_date 2007/06/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The parameters of the minimal supersymmetric standard model appear to require uncomfortably precise adjustment in order to reconcile the electroweak symmetry breaking scale with the lower mass limits on a neutral Higgs scalar boson. This problem can be significantly ameliorated in models with a running gluino mass parameter that is smaller than the wino mass near the scale of unification of gauge couplings. A compressed superpartner mass spectrum results; compared to models with unified gaugino masses, the ratios of the squark and gluino masses to the lightest superpartner mass are reduced. I argue that in this scenario the annihilation of binolike neutralino pairs to top-antitop quark pairs through top-squark exchange can most naturally play the crucial role in ensuring that the thermal relic dark matter density is not too large, with only a small role played by coannihilations. The lightest superpartner mass must then exceed the top-quark mass, and the lighter top squark cannot decay to a top quark. These conditions have important implications for collider searches.