Mini-Split

We study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses m χ 8 TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomalymediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.

Section: Pure Gravity Mediation With Vector Multipletsmentioning

confidence: 99%

Scenarios for gluino coannihilation

Ellis

Evans

Luo

et al. 2016

“…Unification of the gauge couplings at one-loop above M S is recovered by adding two pairs of supermultiplets in the representations (3, 1) 1/3 ⊕ (3, 1) −1/3 . In total, we have therefore added two vectorlike pairs of 5 + 5 of SU (5). This should be reminiscent of gauge mediation scenarios, except that here the doublets mix with the Higgs fields.…”

Section: Type II Fssmmentioning

confidence: 99%

“…Unification in Split SUSY requires µ to be < 10 TeV at 1σ or < 100 TeV at 2σ [5] to match the known value of the Higgs mass is is necessary to have a small tan β; in [5] it was found that the largest value of M S thus compatible with unification and the correct Higgs mass was 10 8 GeV, and that required tan β = 1 -if tan β = 2 instead it becomes 10 6 GeV -but a tuning of the Higgs soft masses to achieve such a value of tan β is not justifiable; just as in the MSSM the RGE running from any given mediation scale tends to drive m 2 Hu < 0 via…”

Section: Jhep11(2015)100mentioning

confidence: 99%

“…However, one key hint to its relevance is the apparent unification of gauge couplings, and if we take this as the main phenomenological motivation, accepting fine-tuning of the electroweak scale -since the fine-tuning of one mass in the Higgs potential has perhaps an anthropic justification -then we are led to study theories where unification arises naturally without tuning of other particle mass thresholds, since the apparent unification of couplings could have no other explanation. This reasoning led to much study of Split Supersymmetry (Split SUSY) [1][2][3]; of particular relevance to this work from the burgeoning literature are [4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

(O)Mega split

Benakli¹,

Goodsell²

2015

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.

“…Previous studies of long-lived particles have primarily focused on supersymmetric models, motivated by the idea of split supersymmetry [3][4][5][6] or simplified toy models with Rparity violation [7][8][9][10][11][12]. Our work is the first analysis of models based on the composite Higgs idea.…”

Section: Jhep03(2016)003mentioning

confidence: 99%

Long-lived, colour-triplet scalars from unnaturalness

Barnard

Cox

Gherghetta

et al. 2016

Long-lived, colour-triplet scalars are a generic prediction of unnatural, or split, composite Higgs models where the spontaneous global-symmetry breaking scale f 10 TeV and an unbroken SU(5) symmetry is preserved. Since the triplet scalars are pseudo NambuGoldstone bosons they are split from the much heavier composite-sector resonances and are the lightest exotic, coloured states. This makes them ideal to search for at colliders. Due to discrete symmetries the triplet scalar decays via a dimension-six term and given the large suppression scale f is often metastable. We show that existing searches for collider-stable R-hadrons from Run-I at the LHC forbid a triplet scalar mass below 845 GeV, whereas with 300 fb −1 at 13 TeV triplet scalar masses up to 1.4 TeV can be discovered. For shorter lifetimes displaced-vertex searches provide a discovery reach of up to 1.8 TeV. In addition we present exclusion and discovery reaches of future hadron colliders as well as indirect limits that arise from modifications of the Higgs couplings.