Cold Dark Matter and b --> s gamma in the Horava-Witten Theory
Abstract
The minimal supersymmetric standard model with complete, partial or no Yukawa unification and radiative electroweak breaking with boundary conditions from the Horava-Witten theory is considered. The parameters are restricted by constraining the lightest sparticle relic abundance by cold dark matter considerations and requiring the b-quark mass after supersymmetric corrections and the branching ratio of b --> s gamma to be compatible with data. Complete Yukawa unification can be excluded. Also, t-b Yukawa unification is strongly disfavored since it requires almost degenerate lightest and next-to-lightest sparticle masses. However, the b-tau or no Yukawa unification cases avoid this degeneracy. The latter with mu<0 is the most natural case. The lightest sparticle mass, in this case, can be as low as about 77 GeV.
Cite
@article{arxiv.hep-ph/0005021,
title = {Cold Dark Matter and b --> s gamma in the Horava-Witten Theory},
author = {S. Khalil and G. Lazarides and C. Pallis},
journal= {arXiv preprint arXiv:hep-ph/0005021},
year = {2008}
}
Comments
16 pages including 4 figures, Revtex, version to appear in Phys. Lett. B