scholarly journals Hybrid anomaly and gravity mediation for electroweak supersymmetry

2018 ◽  
Vol 33 (07) ◽  
pp. 1850035
Author(s):  
Bin Zhu ◽  
Ran Ding ◽  
Tianjun Li

In this paper, we propose a hybrid mediation and hybrid supersymmetry breaking. In particular, the RG-invariant anomaly mediation is considered. Together with additional gravity mediation, the slepton tachyon problem of anomaly mediation is solved automatically. The special properties are that all color sparticles masses fall into several TeV regions due to the large [Formula: see text] and [Formula: see text] which are well beyond the scope of current LHC Run II limits. Unlike the gauge mediation, the dark matter candidate is still the lightest neutralino and the correct dark matter relic density can be realized within the framework of mixed axion-Wino dark matter. Due to the existence of multi-component axion-Wino dark matter, the direct detection cross-section is suppressed to evade the tightest LUX, PandaX bound.

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Melissa van Beekveld ◽  
Wim Beenakker ◽  
Marrit Schutten ◽  
Jeremy De Wit

In this paper we perform for the first time an in-depth analysis of the spectra in the phenomenological supersymmetric Standard Model that simultaneously offer an explanation for the (g-2)_{\mu}(g−2)μ discrepancy \Delta a_{\mu}Δaμ, result in the right dark-matter relic density \Omega_{DM} h^2ΩDMh2 and are minimally fine-tuned. The resulting spectra may be obtained from [1]. To discuss the experimental exclusion potential for our models, we analyse the resulting LHC phenomenology as well as the sensitivity of dark-matter direct detection experiments to these spectra. We find that the latter type of experiments with sensitivity to the spin-dependent dark-matter–nucleon scattering cross section \sigma_{SD,p}σSD,p will probe all of our found solutions.


Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 31
Author(s):  
Elham Aldufeery ◽  
Maien Binjonaid

The neutralino sector of the semi-constrained next-to-minimal supersymmetric standard model is explored under recent experimental constraints, with special attention to dark matter (DM) limits. The effects of the upper and lower bounds of dark matter relic density and recent direct detection constraints on spin-independent and -dependent cross-sections are thoroughly analyzed. Particularly, we show which regions of the parameter space are ruled out due to the different dark matter constraints and the corresponding model-specific parameters: λ,κ,Aλ, and Aκ. We analyze all annihilation and co-annihilation processes (with heavier neutralinos and charginos) that contribute to the dark matter relic density. The mass components of the dark matter candidate, the lightest neutralino χ˜10, are studied, and the decays of heavy neutralinos and charginos, especially χ˜20 and χ˜1+, into the lightest neutralino are examined. We impose semi-universal boundary conditions at the Grand Unified Theory scale, and require a moderate range of tanβ≲10. We find that the allowed parameter space is associated with a heavy mass spectrum in general and that the lightest neutralino is mostly Higgsino with a mass range that resides mostly between 1000 and 1500 GeV. However, smaller mass values can be achieved if the DM candidate is bino-like or singlino-like.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Mathias Becker ◽  
Dominik Döring ◽  
Siddhartha Karmakar ◽  
Heinrich Päs

AbstractWe study the dark matter phenomenology of Standard Model extensions addressing the reported anomaly in the $$R_K$$ R K observable at one-loop. The article covers the case of fermionic singlet DM coupling leptophilically, quarkphilically or amphiphilically to the SM. The setup utilizes a large coupling of the new particle content to the second lepton generation to explain the $$R_K$$ R K anomaly, which in return tends to diminish the dark matter relic density. Further, dark matter direct detection experiments provide stringent bounds even in cases where the dark matter candidate only contributes a small fraction of the observed dark matter energy density. In fact, direct detection rules out all considered models as an explanation for the $$R_K$$ R K anomaly in the case of Dirac dark matter. Conversely, for Majorana dark matter, the $$R_K$$ R K anomaly can be addressed in agreement with direct detection in coannihilation scenarios. For leptophilic dark matter this region only exists for $$M_\text {DM} \lesssim 1000 \, \mathrm {GeV}$$ M DM ≲ 1000 GeV and dark matter is underabundant. Quarkphilic and amphiphilic scenarios even provide narrow regions of parameter space where the observed relic density can be reproduced while offering an explanation to $$R_K$$ R K in agreement with direct detection experiments.


2007 ◽  
Vol 22 (13) ◽  
pp. 931-937 ◽  
Author(s):  
P. H. FRAMPTON

Abelian quiver gauge theories provide candidates for the conformality approach to physics beyond the standard model which possess novel cancellation mechanisms for quadratic divergences. A Z2 symmetry ( R parity) can be imposed and leads naturally to a dark matter candidate which is the Lightest Conformality Particle (LCP), a neutral spin-1 / 2 state with weak interaction annihilation cross-section, mass in the 100 GeV region and relic density of non-baryonic dark matter Ωdm which can be consistent with the observed value Ωdm≃0.24.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Cheng-Wei Chiang ◽  
Giovanna Cottin ◽  
Yong Du ◽  
Kaori Fuyuto ◽  
Michael J. Ramsey-Musolf

Abstract We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV pp collider. We focus on the scenario in which the neutral triplet scalar is stable and contributes to the dark matter relic density. When produced in pp collisions, the charged triplet scalar decays to the neutral component plus a soft pion or soft lepton pair, yielding a disappearing charged track in the detector. We recast current 13 TeV LHC searches for disappearing tracks, and find that the LHC presently excludes a real triplet scalar lighter than 248 (275) GeV, for a mass splitting of 172 (160) MeV with ℒ = 36 fb−1. The reach can extend to 497 (520) GeV with the collection of 3000 fb−1. We extrapolate the 13 TeV analysis to a prospective 100 TeV pp collider, and find that a ∼ 3 TeV triplet scalar could be discoverable with ℒ = 30 ab−1, depending on the degree to which pile up effects are under control. We also investigate the dark matter candidate in our model and corresponding present and prospective constraints from dark matter direct detection. We find that currently XENON1T can exclude a real triplet dark matter lighter than ∼ 3 TeV for a Higgs portal coupling of order one or larger, and the future XENON20T will cover almost the entire dark matter viable parameter space except for vanishingly small portal coupling.


Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 991
Author(s):  
Jan Kalinowski ◽  
Tania Robens ◽  
Dorota Sokołowska ◽  
Aleksander Filip Żarnecki

We present cross-section expectations for various processes and collider options, for benchmark scenarios of the Inert Doublet Model, a Two Higgs Doublet Model with a dark matter candidate. The proposed scenarios are consistent with current dark matter constraints, including the most recent bounds from the XENON1T experiment and relic density, as well as with known collider and low-energy limits. These benchmarks, chosen in earlier work for studies at e+e− colliders, exhibit a variety of kinematic features that should be explored at current and future runs of the LHC. We provide cross sections for all relevant production processes at 13 TeV, 27 TeV and 100 TeV proton collider, as well as for a possible 10 TeV and 30 TeV muon collider.


2017 ◽  
Vol 32 (22) ◽  
pp. 1750131
Author(s):  
Karim Ghorbani ◽  
Parsa Hossein Ghorbani

The ATLAS report in August 2016 provided an upper limit for the pp[Formula: see text][Formula: see text][Formula: see text]diboson and [Formula: see text] cross-sections. We consider a pseudoscalar-mediated fermionic dark matter together with gluon and photon effective operators interacting with the pseudoscalar. Choosing the resonance mass being [Formula: see text], 750 GeV and 2 TeV, beside the relic density and the invisible Higgs decay constraints we constrain more the space of parameters with the diboson and [Formula: see text] cross-section upper bounds. We finally provide some benchmarks consistent with all the constraints. Having exploited a pseudoscalar mediator, the DM-nucleon cross-section is velocity suppressed so that the model evades easily the bounds put by the future direct detection experiments such as XENON1T.


2010 ◽  
Vol 25 (11n12) ◽  
pp. 976-982 ◽  
Author(s):  
JIN MIN YANG

We briefly review the supersymmetric explanation for the cosmic dark matter. Although the neutralino in the minimal supersymmetric model (MSSM), the next-to-minimal supersymmetric model (NMSSM) and the nearly minimal supersymmetric model (nMSSM) can naturally explain the dark matter relic density, the PAMELA result can hardly be explained in these popular models. In the general singlet extension of the MSSM, both the PAMELA result and the relic density can be explained by the singlino-like neutralino. Such singlino-like neutralinos annihilate into the singlet-like Higgs bosons, which are light enough to decay dominantly to muons or electrons, and the annihilation cross section can be greatly enhanced by the Sommerfeld effect via exchanging a light CP-even singlet-like Higgs boson. In this scenario, in order to meet the stringent LEP constraints, the SM-like Higgs boson tends to decay into the singlet Higgs pairs instead of [Formula: see text] and consequently it will give a multi-muon signal hSM → aa → 4µ or hSM → hh → 4a → 8µ at the LHC.


2015 ◽  
Vol 30 (15) ◽  
pp. 1530041 ◽  
Author(s):  
Eung Jin Chun

In a supersymmetric U(1)′ seesaw model, a right-handed sneutrino can be a good thermal dark matter candidate if the extra gaugino [Formula: see text] is light enough to provide an appropriate annihilation cross-section through a t-channel diagram. We first discuss how right thermal relic density of the right-handed sneutrino dark matter can arise and then explore lepton number and flavor violating signatures followed by cascade production of [Formula: see text] from the third generation squarks at the LHC.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Shu-Yuan Guo ◽  
Zhi-Long Han

Abstract In this work, we make a detailed discussion on the phenomenology of the scotogenic Dirac model, which could accommodate the Dirac neutrino mass and dark matter. We have studied the lepton-flavor-violating (LFV) processes in this model, which are mediated by the charged scalar ϕ± and heavy Dirac fermions Ni. The experimental bounds, especially given by decays μ → eγ and μ → 3e, have put severe constraints on the Yukawa couplings yΦ and masses mN1, mϕ. We select the heavy Dirac fermion N1 as dark matter candidate and find the correct relic density will be reached basically by annihilating through another Yukawa coupling yχ. After satisfying LFV and dark matter relic density constraints, we consider the indirect detections of dark matter annihilating into leptons. But the constraints are relatively loose, only the τ+τ− channel can impose a mild excluding capability. Then we make a detailed discussion on the dark matter direct detections. Although two Yukawa couplings can both contribute to the direct detection processes, more attention has been paid on the yΦ-related processes as the yχ-related process is bounded loosely. The current and future direct detection experiments have been used to set constraints on the Yukawa couplings and masses. The current direct detections bounds are relatively loose and can barely exclude more parameter region beyond the LFV. For the future direct detection experiments, the excluding capacities can be improved due to larger exposures. The detecting capabilities in the large mass region have not been weakened as the existence of mass enhancement from the magnetic dipole operator $$ {\mathcal{O}}_{\mathrm{mag}.} $$ O mag . . At last, we have briefly discussed the collider signal searching in this model, the most promising signature is pair produced ϕ+ϕ− and decay into the signal of ℓ+ℓ− + ɆT. The exclusion limits from collider on mN1 and mϕ have provided a complementary detecting capability compared to the LFV and dark matter detections.


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