Varying the universality of supersymmetry-breaking contributions to MSSM Higgs boson masses

Abstract

which they are independently nonuniversal (NUHM2). We show how the NUHM1 scenarios generalize the ðm1=2 ;m 0Þ planes of the CMSSM by allowing eitheror 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.