Scenarios for gluino coannihilation

Ellis, John; Evans, Jason L.; Luo, Feng; Olive, Keith A.

doi:10.1007/jhep02(2016)071

Cited by 43 publications

(49 citation statements)

References 162 publications

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“…In particular, the neutralino relic density in the TeV regime must be regulated by either some strong resonant process or co-annihilation. Indeed, the strongest such process involves the co-annihilation with the gluino [33][34][35][36]. Pushing the mass scales to their limit (when the neutralino and gluino masses are degenerate), an upper limit to the neutralino mass of roughly 8 TeV was found [34][35][36].…”

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confidence: 99%

Case for an EeV Gravitino

2017

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We consider the possibility that supersymmetry is broken above the inflationary mass scale and that the only "low" energy remnant of supersymmetry is the gravitino with mass of order the EeV scale. The gravitino in this class of models becomes a candidate for the dark matter of the Universe. To avoid the over-production of gravitinos from the decays of the next-to-lightest supersymmetric particle we argue that the supersymmetric spectrum must lie above the inflationary mass scale (MSUSY > 10 −5 MP ∼ 10 13 GeV). [5,6]. This may indicate one of the following: 1) low energy supersymmetry is still around the corner waiting to be discovered at a slightly higher energy scale [6,7]; 2) part of the supersymmetric spectrum lies at very high energy as in split supersymmetry [8]; 3) essentially the entire supersymmetric spectrum lies at very high energy as in supersplit supersymmetry [9] (aka the Standard Model). Here, we consider the possibility that the only remnant of supersymmetry surviving down to energies significantly below the Planck scale 1 is the gravitino.

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confidence: 99%

Case for an EeV Gravitino

2017

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“…Another important effect that can lengthen the stop coannihilation strip is bound-state formation [75,76,[94][95][96]. When dark matter froze out, at a temperature T ∼ mt /25 QC D , QCD was a relatively long-range force, and stronglyinteracting particles could form bound states.…”

Section: Bound-state Effects In Stop Coannihilationmentioning

confidence: 99%

“…Examples of possible coannihilation partners include sleptons [39][40][41][42][43][44][45][46][47], electroweak inos [48][49][50][51], squarks [52][53][54][55][56][57][58][59][60][61][62][63] and gluinos [63][64][65][66][67][68][69][70][71][72][73][74][75][76]. Coannihilation of the LSP with the lighter stau slepton has been explored extensively, and is now almost excluded by LHC searches [46,47].…”

Section: Introductionmentioning

confidence: 99%

Stop coannihilation in the CMSSM and SubGUT models

Ellis

Evans²,

Luo

et al. 2018

Eur. Phys. J. C

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Stop coannihilation may bring the relic density of heavy supersymmetric dark matter particles into the range allowed by cosmology. The efficiency of this process is enhanced by stop-antistop annihilations into the longitudinal (Goldstone) modes of the W and Z bosons, as well as by Sommerfeld enhancement of stop annihilations and the effects of bound states. Since the couplings of the stops to the Goldstone modes are proportional to the trilinear soft supersymmetry-breaking A-terms, these annihilations are enhanced when the A-terms are large. However, the Higgs mass may be reduced below the measured value if the A-terms are too large. Unfortunately, the interpretation of this constraint on the stop coannihilation strip is clouded by differences between the available Higgs mass calculators. For our study, we use as our default calculator FeynHiggs 2.13.0, the most recent publicly available version of this code. Exploring the CMSSM parameter space, we find that along the stop coannihilation strip the masses of the stops are severely split by the large A-terms. This suppresses the Higgs mass drastically for μ and A 0 > 0, whilst the extent of the stop coannihilation strip is limited for A 0 < 0 and either sign of μ. However, in sub-GUT models, reduced renormalization-group running mitigates the effect of the large A-terms, allowing larger LSP masses to be consistent with the Higgs mass calculation. We give examples where the dark matter particle mass may reach 8 TeV.

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“…The CMSSM offers limited prospects for coannihilation, and examples that have been studied in some detail include coannihilation with the lighter stau slepton,τ 1 [28][29][30][31][32][33][34][35], or the lighter stop squark,t 1 [36][37][38][39][40][41][42][43][44][45]. Other models offer the possibilities of different coannihilation partners, such as the lighter chargino,χ ± 1 [25,[46][47][48][49][50], some other slepton [27] or squark flavour [51], or the gluino [52][53][54][55][56][57][58][59][60][61][62][63][64][65]. In particular, the pMSSM allows for all these possibilities, potentially also in combination [27].…”

Section: Introductionmentioning

confidence: 99%

Likelihood analysis of the sub-GUT MSSM in light of LHC 13-TeV data

et al. 2018

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We describe a likelihood analysis using MasterCode of variants of the MSSM in which the soft supersymmetry-breaking parameters are assumed to have universal values at some scale M in below the supersymmetric grand unification scale M GUT , as can occur in mirage mediation and other models. In addition to M in , such 'sub-GUT' models have the 4 parameters of the CMSSM, namely a common gaugino mass m 1/2 , a common soft supersymmetrybreaking scalar mass m 0 , a common trilinear mixing parameter A and the ratio of MSSM Higgs vevs tan β, assuming that the Higgs mixing parameter μ > 0. We take into account constraints on strongly-and electroweakly-interacting sparticles from ∼ 36/fb of LHC data at 13 TeV and the LUX and 2017 PICO, XENON1T and PandaX-II searches for dark matter scattering, in addition to the previous LHC and dark matter constraints as well as full sets of flavour and electroweak constraints. We find a preference for M in ∼ 10 5 to 10 9 GeV, with M in ∼ M GUT disfavoured by χ 2 ∼ 3 due to the BR(B s,d → μ + μ − ) constraint. The lower limits on strongly-interacting sparticles are largely determined by LHC searches, and similar to those in the CMSSM. We find a preference for the LSP to be a Bino or Higgsino with mχ0 1 ∼ 1 TeV, with annihilation via heavy Higgs bosons a e-mail: j.costa15@imperial.ac.uk H/A and stop coannihilation, or chargino coannihilation, bringing the cold dark matter density into the cosmological range. We find that spin-independent dark matter scattering is likely to be within reach of the planned LUX-Zeplin and XENONnT experiments. We probe the impact of the (g − 2) μ constraint, finding similar results whether or not it is included.

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Scenarios for gluino coannihilation

Cited by 43 publications

References 162 publications

Case for an EeV Gravitino

Case for an EeV Gravitino

Stop coannihilation in the CMSSM and SubGUT models

Likelihood analysis of the sub-GUT MSSM in light of LHC 13-TeV data

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