Postcards from oases in the desert: phenomenology of SUSY with intermediate scales

TL;DR

This paper explores how intermediate-scale matter fields in supersymmetric models alter gauge coupling evolution, significantly impacting the low-energy spectrum, dark matter compatibility, and potential LHC observables.

Contribution

It provides a parameterization of intermediate scale models without large Yukawa couplings and analyzes their phenomenological implications.

Findings

Scalar over gaugino mass ratios increase

Neutralino dark matter regions are drastically modified

Potential LHC observables for testing intermediate scale physics

Abstract

The presence of new matter fields charged under the Standard Model gauge group at intermediate scales below the Grand Unification scale modifies the renormalization group evolution of the gauge couplings. This can in turn significantly change the running of the Minimal Supersymmetric Standard Model parameters, in particular the gaugino and the scalar masses. In the absence of new large Yukawa couplings we can parameterise all the intermediate scale models in terms of only two parameters controlling the size of the unified gauge coupling. As a consequence of the modified running, the low energy spectrum can be strongly affected with interesting phenomenological consequences. In particular, we show that scalar over gaugino mass ratios tend to increase and the regions of the parameter space with neutralino Dark Matter compatible with cosmological observations get drastically modified. Moreover, we discuss some observables that can be used to test the intermediate scale physics at the LHC in a wide class of models.