scholarly journals Searching for supersymmetry and its avatars

2019 ◽  
Vol 377 (2161) ◽  
pp. 20190069 ◽  
Author(s):  
John Ellis
Keyword(s):  
Dark Matter ◽  
Higgs Mass ◽  
Cold Dark Matter ◽  
Hadron Collider ◽  
Charged Particles ◽  
New Physics ◽  
Supersymmetric Particle ◽  
Laser Arrays ◽  
Super Symmetry ◽  
The Aesthetic

Why continue looking for supersymmetry? Over and above the aesthetic and theoretical motivations from string theory, there are several longstanding pheno- menological motivations for TeV-scale super- symmetry, such as the electroweak scale, and the lightest supersymmetric particle as cold dark matter. Run 1 of the Large Hadron Collider (LHC) has actually provided three extra motivations, namely the stabilization of the electroweak vacuum, and successful predictions for the Higgs mass and couplings. How to look for it? There are several examples of emergent supersymmetry, the most recent being on the surfaces of topological insulators, and some sort of effective supersymmetry could be useful for boosting the power of laser arrays. At the LHC, attention is moving towards signatures that had previously been neglected, such as long-lived charged particles—which might be an opportunity for the MoEDAL experiment. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

scholarly journals MSSM Dark Matter in Light of Higgs and LUX Results

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
W. Abdallah ◽  
S. Khalil
Keyword(s):  
Dark Matter ◽  
Parameter Space ◽  
Higgs Mass ◽  
Hadron Collider ◽  
Supersymmetric Particle ◽  
Gluino Mass ◽  
Mass Limit ◽  
Narrow Region ◽  
Relic Abundance ◽  
Rule Out

The constraints imposed on the Minimal Supersymmetric Standard Model (MSSM) parameter space by the Large Hadron Collider (LHC) Higgs mass limit and gluino mass lower bound are revisited. We also analyze the thermal relic abundance of lightest neutralino, which is the Lightest Supersymmetric Particle (LSP). We show that the combined LHC and relic abundance constraints rule out most of the MSSM parameter space except a very narrow region with very largetan⁡β  (~50). Within this region, we emphasize that the spin-independent scattering cross section of the LSP with a proton is less than the latest Large Underground Xenon (LUX) limit by at least two orders of magnitude. Finally, we argue that nonthermal Dark Matter (DM) scenario may relax the constraints imposed on the MSSM parameter space. Namely, the following regions are obtained:m0≃O(4) TeV andm1/2≃600 GeV for lowtan⁡β  (~10);m0~m1/2≃O(1) TeV orm0≃O(4) TeV andm1/2≃700 GeV for largetan⁡β  (~50).

scholarly journals Future prospects for the minimal supersymmetric standard model

2021 ◽  
pp. 2150188
Author(s):  
Shehu AbdusSalam ◽  
Safura S. Barzani ◽  
Mohammadreza Noormandipour
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Cold Dark Matter ◽  
Direct Detection ◽  
Hadron Collider ◽  
Hadron Colliders ◽  
Future Prospects ◽  
Lower Limits

Experimental collaborations for the large hadron collider conducted various searches for supersymmetry. In the absence of signals, lower limits were put on sparticle masses but usually within frameworks with (over-)simplifications relative to the entire indications by supersymmetry models. For complementing current interpretations of experimental bounds, we introduce a 30-parameter version of the R-parity conserving Minimal Supersymmetric Standard Model (MSSM-30). Using a sample of the MSSM-30 which are in harmony with cold dark matter, flavor and precision electroweak constraints, we explicitly show the prospects for assessing neutralino candidate dark matter in contrast to future searches for supersymmetry. The MSSM-30-parameter regions that are beyond reach to dark matter direct detection experiments could be probed by future hadron–hadron colliders.

scholarly journals Realistic Calculations for Cold Dark Matter Detection Rates

2020 ◽  
Vol 13 ◽  
pp. 283
Author(s):  
T. S. Kosmas ◽  
M. Kortelainen ◽  
J. Suhonen ◽  
J. Toivanen
Keyword(s):  
Dark Matter ◽  
Nuclear Structure ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Scattering Problem ◽  
Realistic Model ◽  
Supersymmetric Particle ◽  
Detection Rates ◽  
Model Spaces ◽  
Event Rates

The scattering of the cold dark matter (CDM) candidate LSP (Lightest Supersymmetric Particle) off nuclei is investigated. We focus on the nuclear-structure aspects of the LSP-nucleus scattering problem and computed the associated event rates as well as the annual modulation signals for the 23Na, 71Ga, 73Ge and 127I CDM detectors by using the nuclear shell model in realistic model spaces and exploiting microscopic effective two-body interactions. Large-scale computations had to be performed in order to achieve convergence of the results. The relevance of the spin-dependent and coherent channels for the event rates is discussed, from both the nuclear structure and the SUSY-model viewpoints.

scholarly journals CP VIOLATIONS (AND MORE) AFTER THE FIRST TWO YEARS OF LHCB

2013 ◽  
Vol 53 (A) ◽  
pp. 528-533
Author(s):  
Giulio Auriemma
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Particle Physics ◽  
Hadron Collider ◽  
Higgs Sector ◽  
New Physics ◽  
Baryon Asymmetry ◽  
Open Problems ◽  
Cp Violations ◽  
The Standard Model

The most interesting cosmological open problems, baryon asymmetry, dark matter, inflation and dark energy, are not explained by the standard model of particle physics (SM). The final<br />goal of the Large Hadron Collider an experimental verification of the SM in the Higgs sector, and also a search for evidence of new physics beyond it. In this paper we will report some of the results obtained in 2010 and 2011, from the LHCb experiment dedicated to the study of CP violations and rare decays of heavy quarks.

scholarly journals Way-out to the gravitino problem in intersecting D-brane Pati–Salam models

2016 ◽  
Vol 31 (19) ◽  
pp. 1650111 ◽  
Author(s):  
Andrea Addazi ◽  
Maxim Yu Khlopov
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
High Energy ◽  
Indirect Detection ◽  
Supersymmetric Particle ◽  
Cosmological Time ◽  
Neutrino Sector ◽  
Very High Energy ◽  
Very High ◽  
Parity Breaking

We discuss the gravitino problem in the context of the exotic see-saw mechanism for neutrinos and leptogenesis, UV completed by intersecting D-branes Pati–Salam models. In the exotic see-saw model, supersymmetry is broken at high scales M[Formula: see text] 109 GeV and this seems in contradiction with gravitino bounds from inflation and baryogenesis. However, if gravitino is the lightest stable supersymmetric particle, it will not decay into other SUSY particles, avoiding the gravitino problem and providing a good cold dark matter (CDM). Gravitini are super heavy dark particles and they can be produced by non-adiabatic expansion during inflation. Intriguingly, from bounds on the correct abundance of dark matter (DM), we also constrain the neutrino sector. We set a limit on the exotic instantonic coupling of [Formula: see text] 10[Formula: see text]–10[Formula: see text]. This also sets constrains on the Calabi–Yau compactifications and on the string scale. This model strongly motivates very high energy DM indirect detection of neutrini and photons of 10[Formula: see text]–10[Formula: see text] GeV: gravitini can decay on them in a cosmological time because of soft R-parity breaking effective operators.

THREE GENERATIONS: A PREDICTION FULFILLED

1990 ◽  
Vol 05 (09) ◽  
pp. 645-651
Author(s):  
JORGE L. LOPEZ ◽  
D.V. NANOPOULOS
Keyword(s):  
Dark Matter ◽  
Strong Correlation ◽  
Planck Scale ◽  
New Physics ◽  
Supersymmetric Particle ◽  
Three Generations ◽  
Unified Theories ◽  
The Universe

We recall the theoretical arguments that led us more than ten years ago to predict that there are only three generations. Quark-lepton mass relations (mb/mτ ≈ 2.8), as universally come out from unified theories at superhigh energies (close to the Planck scale), are the key point. We further argue that fractional deviations from Nν=3 may signal new physics. The supersymmetric decay Z→ÑÑ, with Ñ the lightest neutralino and lightest supersymmetric particle (LSP), easily fits the bill. In the specific case of flipped (SU(5)×U(1)) unification, there is a strong correlation between mt≈ O(90 ± 10) GeV, slepton masses of O(50 GeV) and the closure of the Universe due to Ñ dark matter, while ΔNν ≈ (0.1–0.5).

scholarly journals A REVIEW OF NATURALNESS AND DARK MATTER PREDICTION FOR THE HIGGS MASS IN MSSM AND BEYOND

2012 ◽  
Vol 27 (02) ◽  
pp. 1230003 ◽  
Author(s):  
S. CASSEL ◽  
D. M. GHILENCEA
Keyword(s):  
Dark Matter ◽  
Higgs Mass ◽  
Higgs Sector ◽  
New Physics ◽  
Fine Tuning ◽  
Quantum Corrections ◽  
Electroweak Scale ◽  
A Value ◽  
8 Tev ◽  
Effective Operators

Within a two-loop leading-log approximation, we review the prediction for the lightest Higgs mass (mh) in the framework of constrained MSSM (CMSSM), derived from the naturalness requirement of minimal fine-tuning (Δ) of the electroweak scale, and dark matter consistency. As a result, the Higgs mass is predicted to be just above the LEP2 bound, mh = 115.9±2 GeV , corresponding to a minimal Δ = 17.8, the value obtained from consistency with electroweak and WMAP (3σ) constraints, but without the LEP2 bound. Due to quantum corrections (largely QCD ones for mh above LEP2 bound), Δ grows ≈ exponentially on either side of the above value of mh, which stresses the relevance of this prediction. A value mh>121 (126) GeV cannot be accommodated within the CMSSM unless one accepts a fine-tuning cost worse than Δ>100 (1000), respectively. We review how the above prediction for mh and Δ changes under the addition of new physics beyond the MSSM Higgs sector, parametrized by effective operators of dimensions d = 5 and d = 6. For d = 5 operators, one can obtain values mh as large as 130 GeV with an acceptable Δ<10. The size of the supersymmetric correction that each individual operator of d = 6 brings to the value of mh for points with Δ<100 (<200), is found to be small, of few ≤4 GeV (≤6 GeV) respectively, for M = 8 TeV where M is the scale of new physics. This value decreases (increases) by approximately 1 GeV for a 1 TeV increase (decrease) of the scale M. The relation of these results to the Atlas/CMS supersymmetry exclusion limits is presented together with their impact for the CMSSM regions of lowest fine-tuning.

scholarly journals Electroweak symmetry non-restoration from dark matter

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Oleksii Matsedonskyi ◽  
James Unwin ◽  
Qingyun Wang
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Higgs Mass ◽  
Direct Detection ◽  
Higgs Doublet ◽  
New Physics ◽  
Electroweak Symmetry ◽  
The Standard Model ◽  
New States ◽  
Potential Remedy

Abstract Restoration of the electroweak symmetry at temperatures around the Higgs mass is linked to tight phenomenological constraints on many baryogenesis scenarios. A potential remedy can be found in mechanisms of electroweak symmetry non-restoration (SNR), in which symmetry breaking is extended to higher temperatures due to new states with couplings to the Standard Model. Here we show that, in the presence of a second Higgs doublet, SNR can be realized with only a handful of new fermions which can be identified as viable dark matter candidates consistent with all current observational constraints. The competing requirements on this class of models allow for SNR at temperatures up to ∼TeV, and imply the presence of sub-TeV new physics with sizable interactions with the Standard Model. As a result this scenario is highly testable with signals in reach of next-generation collider and dark matter direct detection experiments.

Searches for exotica and dark matter with neutrino telescopes

2019 ◽  
Vol 377 (2161) ◽  
pp. 20190084
Author(s):  
A. Margiotta
Keyword(s):  
Dark Matter ◽  
Cosmic Radiation ◽  
Charged Particles ◽  
New Physics ◽  
Magnetic Monopoles ◽  
Neutrino Telescopes ◽  
The Standard Model ◽  
Large Water ◽  
The Universe ◽  
Detector Volume

Neutrino telescopes are designed to search for neutrino sources in the Universe, exploiting the Cherenkov light emitted along the path of the charged particles produced in interactions occurring close to the detector volume. Their huge size and the shield offered by large water or ice overburden make them excellent tools to search for exotic and rare particles in the cosmic radiation. In particular, they are sensitive to particles not predicted by the Standard Model that could be messenger of new physics. An overview of the experimental scenario and the relevant results obtained looking for magnetic monopoles, dark matter candidates and other exotic relic particles with neutrino telescopes is given, together with the description of possible new perspectives. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

scholarly journals SUSY INTO DARKNESS: HEAVY SCALARS IN THE CMSSM

2013 ◽  
Vol 28 (15) ◽  
pp. 1350061 ◽  
Author(s):  
VAN E. MAYES
Keyword(s):  
Dark Matter ◽  
Parameter Space ◽  
Cross Sections ◽  
Higgs Mass ◽  
Cold Dark Matter ◽  
Direct Detection ◽  
Percent Level ◽  
Relic Density ◽  
The One ◽  
Near Future

A survey of the mSUGRA/CMSSM parameter space is presented. The viable regions of the parameter space which satisfy standard experimental constraints are identified and discussed. These constraints include a 124–127 GeV mass for the lightest CP-even Higgs and the correct relic density for cold dark matter. The superpartner spectra corresponding to these regions fall within the well-known hyperbolic branch and are found to possess sub-TeV neutralinos and charginos, with mixed Bino/Higgsino LSP's with 200–800 GeV masses. In addition, the models possess ~3–4 TeV gluino masses and heavy squarks and sleptons with masses [Formula: see text]. Spectra with a Higgs mass mh≅125 GeV and a relic density 0.105 ≤ Ωχ0h2≤ 0.123 are found to require EWFT at around the one-percent level, while those spectra with a much lower relic density require EWFT of only a few percent. Moreover, the spin-independent neutralino–proton direct detection cross-sections are found to be below or within the XENON100 2σ limit and should be experimentally accessible now or in the near future. Finally, it is pointed out that the supersymmetry breaking soft terms corresponding to these regions of the mSUGRA/CMSSM parameter space (m0∝ m1/2with [Formula: see text] and A0= -m1/2) may be obtained from general flux-induced soft terms in Type IIB flux compactifications with D3 branes.

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