Natural 125 GeV Higgs boson in the MSSM from focus point supersymmetry with A -terms

108

Naturalness arguments applied to supersymmetric theories imply a spectrum containing four light higgsinos Z 1,2 and W ± 1 with masses ∼ 100 − 300 GeV (the closer to M Z , the more natural). The compressed mass spectrum and associated low energy release from W 1 and Z 2 three-body decay makes higgsinos difficult to detect at LHC14, while the other sparticles might be heavy, and possibly even beyond LHC14 reach. In contrast, the International Linear e + e − Collider (ILC) with √ s > 2m(higgsino) would be a higgsino factory in addition to a Higgs boson factory and would serve as a discovery machine for natural SUSY! In this case, both chargino and neutralino production occur at comparable rates, and lead to observable signals above SM backgrounds. We examine two benchmark cases, one just beyond the LHC8 reach with W 1 ( Z 2 ) − Z 1 mass gap of 15 (21) GeV, and a second more difficult case beyond even the LHC14 reach, where the mass gap is just 10 GeV, close to its minimum in models with no worse than 3% finetuning. The signal is characterized by low visible energy events together with E T in the one or two jets +1ℓ channel from chargino production, and in the opposite sign, sameflavour, acoplanar dilepton channel from Z 1 Z 2 production. For both cases, we find that the signal is observable above backgrounds from the usual 2 → 2 SM events and from γγ collisions with just a few fb −1 of integrated luminosity. We also show that with an integrated luminosity of 100 fb −1 , it should be possible to extract W 1 and Z 1 masses at 2-3% level from chargino events if the mass gap is ≥ 15 GeV, and neutralino masses at the sub-percent level from neutralino events. The latter should also allow a determination of m Z 2 − m Z 1 at the 200 MeV level. These measurements would point to higgsinos as the origin of new physics and strongly suggest a link to a natural origin for W , Z and h masses.

Section: Jhep06(2014)172mentioning

confidence: 99%

Physics at a Higgsino factory

Baer

Barger

Mickelson

et al. 2014

108

“…All these significantly jeopardize the naturalness of MSSM with a standard sparticle spectrum. Therefore, it is imperative to consider the possibly hidden parameters space where the theory maintains naturalness, and look for other strategies for verifying such natural SUSY models at the LHC [13][14][15][16][17]. In this work, we investigate the possibility of monojet signals induced by light higgsinos at 14 TeV high-luminosity LHC(HL-LHC) as a probe of natural SUSY.…”

Section: Introductionmentioning

confidence: 99%

Probing light higgsinos in natural SUSY from monojet signals at the LHC

Han

Kobakhidze

Liu

et al. 2014

126

123

We investigate a strategy to search for light, nearly degenerate higgsinos within the natural MSSM at the LHC. We demonstrate that the higgsino mass range µ in 100 − 160 GeV, which is preferred by the naturalness, can be probed at 3σ significance through the monojet search at 14 TeV HL-LHC with 3000 fb −1 luminosity. The proposed method can also probe certain region in the parameter space for the lightest neutralino with a high higgsino purity, that cannot be reached by planned direct detection experiments at XENON-1T(2017).

“…Even if the higgsino LSP is realized in some ways such as considered in refs. [94,95], light bino and wino are severely constrained by the direct detections. The direct detection constraints push up the gluino mass far above the experimental reach and such a heavy gluino indicates all other sparticles are also hopeless to be discovered except in some special cases.…”

Section: Resultsmentioning

confidence: 99%

Study of dark matter physics in non-universal gaugino mass scenario

Kawamura

Omura

2017

Abstract:We study dark matter physics in the Minimal Supersymmetric Standard Model with non-universal gaugino masses at the unification scale. In this scenario, the specific ratio of wino and gluino masses realizes the electro-weak scale naturally and achieves 125 GeV Higgs boson mass. Then, relatively light higgsino is predicted and the lightest neutral particle, that is dominantly given by the neutral component of higgsino, is a good dark matter candidate. The direct detection of the dark matter is sensitive to not only a higgsino mass but also gaugino masses significantly. The upcoming XENON1T experiment excludes the parameter region where bino or gluino is lighter than about 2.5 TeV if the higgsino and the gaugino mass parameters have same signs. We see that the direct detection of dark matter gives stronger bound than the direct search at the LHC experiment when higgsino gives sizable contribution to the dark matter abundance.