Compressed supersymmetry and natural neutralino dark matter from top squark-mediated annihilation to top quarks
- Physics Department, Northern Illinois University, DeKalb, Illinois 60115 (United States) and Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois 60510 (United States)
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.
- OSTI ID:
- 20929567
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 75, Issue 11; Other Information: DOI: 10.1103/PhysRevD.75.115005; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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