English

Against Tachyophobia

High Energy Physics - Phenomenology 2008-11-26 v1

Abstract

We examine the possible extension of the parameter space of the minimal supersymmetric extension of the Standard Model (MSSM), as expressed via the renormalization-group equations in terms of universal soft supersymmetry-breaking terms at the unification scale, to include tachyonic input scalar masses. Many models with negative masses-squared for scalars at the unification scale may be viable because the small sizes of the masses-squared allow them to change signs during the renormalization-group evolution to the electroweak scale. However, in many cases, there is, in addition to the electroweak vacuum, a much deeper high-scale vacuum located along some F- and D-flat direction in the effective potential for the MSSM. We perform a numerical search for such vacua in both the CMSSM and the NUHM. We discuss the circumstances under which the existence of such a deep charge- and color-breaking vacuum is consistent with standard cosmology. A crucial role is played by the inflation--induced scalar masses, whereas thermal effects are often irrelevant.

Keywords

Cite

@article{arxiv.0806.3648,
  title  = {Against Tachyophobia},
  author = {John Ellis and Joel Giedt and Oleg Lebedev and Keith Olive and Mark Srednicki},
  journal= {arXiv preprint arXiv:0806.3648},
  year   = {2008}
}

Comments

24 pages, 4 figures

R2 v1 2026-06-21T10:53:21.977Z