2008/05/15 by John Ellis, Keith A. Olive, Pearl Sandick · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1103/physrevd.78.075012
published as Phys.Rev.D78:075012,2008 · 39 pages, 16 figures
arxiv created 2008/05/15 · openalex publication_date 2008/10/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We consider the minimal supersymmetric extension of the standard model (MSSM) with varying amounts of nonuniversality in the soft supersymmetry-breaking contributions to the Higgs scalar masses. In addition to the constrained MSSM (CMSSM) in which these are universal with the soft supersymmetry-breaking contributions to the squark and slepton masses at the input GUT scale, we consider scenarios in which both the Higgs scalar masses are nonuniversal by the same amount (NUHM1), and scenarios in which they are independently nonuniversal (NUHM2). We show how the NUHM1 scenarios generalize the (m1/2,m0) planes of the CMSSM by allowing either \ensuremathμ or mA to take different (fixed) values and we also show how the NUHM1 scenarios are embedded as special cases of the more general NUHM2 scenarios. Generalizing from the CMSSM, we find regions of the NUHM1 parameter space that are excluded because the lightest supersymmetric particle (LSP) is a selectron. We also find new regions where the neutralino relic density falls within the range preferred by astrophysical and cosmological measurements, thanks to rapid annihilation through direct-channel Higgs poles, or coannihilation with selectrons, or because the LSP composition crosses over from being mainly bino to mainly Higgsino. Generalizing further to the NUHM2, we find regions of its parameter space where a sneutrino is the LSP, and others where neutralino coannihilation with sneutrinos is important for the relic density. In both the NUHM1 and the NUHM2, there are slivers of parameter space where the LHC has fewer prospects for discovering sparticles than in the CMSSM, because either m1/2 and/or m0 may be considerably larger than in the CMSSM.