(O)Mega split

Abstract

We study two realisations of the Fake Split Supersymmetry Model (FSSM), the simplest model that can easily reproduce the experimental value of the Higgs mass for an arbitrarily high supersymmetry scale M S , as a consequence of swapping higgsinos for equivalent states, fake higgsinos, with suppressed Yukawa couplings. If the LSP is identified as the main Dark matter component, then a standard thermal history of the Universe implies upper bounds on M S , which we derive. On the other hand, we show that renormalisation group running of soft masses above M S barely constrains the model -in stark contrast to Split Supersymmetry -and hence we can have a "Mega Split" spectrum even with all of these assumptions and constraints, which include the requirements of a correct relic abundance, a gluino life-time compatible with Big Bang Nucleosynthesis and absence of signals in present direct detection experiments of inelastic dark matter. In an appendix we describe a related scenario, Fake Split Extended Supersymmetry, which enjoys similar properties.

Off-trail SUSY

“…To summarise, the success of FSSM rests on simultaneously switching off the higgsinos Yukawa couplings while conserving stronger gauge couplings than High scale SUSY thanks to the presence of extra states at the TeV-scale. Similar arguments also explain why the Extended Split SUSY scenario presented in the Appendix of [30] predicts lower Higgs mass than the three scenarios described here. It keeps the suppression of (· · ·g n · · · ) terms while it enhances the gauge couplings.…”

“…Since Fgluinos decay must proceed via mixing with the usual gluinos, their decay rates are even more suppressed. In [29,30] we show that τg , the F-gluino life-time is given by…”

“…This is one aim of FSSM [29] and [30]. There are different realisations of the FSSM scenario (see also [31] for yet another different realisation and for a motivation of fake gluinos):…”

“…The success of FSSM is illustrated in Figure 1. Technical details of the computations can be found in [29] and [30]. Here, we would like to pinpoint the origin of the differences in the predictions for the Higgs mass.…”

Matching renormalisable couplings: simple schemes and a plot

“…In particular, this is an increasingly important approach to calculating the Higgs mass from a top-down theory, providing a more accurate calculation than a fixed-order one once new particles that couple to the Higgs are above a few TeV. It is the only approach to constraining the Higgs mass in split supersymmetry [12][13][14] where new physics could be around 100 − 10 5 TeV [15,16]; high-scale supersymmetry [15,[17][18][19][20] where it could be around 10 7 − 10 9 TeV; the FSSM [21,22] where it could be as high as the GUT/Planck scale, etc. Moreover, there is also a parallel effort considering the low-energy theory to be a simple non-supersymmetric extension of the SM such as a Two-Higgs-Doublet Model (THDM) [23][24][25][26][27], and then it is very interesting to match these theories to new physics at a (much) higher scale.…”