155 research outputs found
Upper bounds on the mass of the lightest neutralino
We derive the general upper bounds on the mass of the lightest neutralino, as a function of the gluino mass, in different supersymmetry breaking models with minimal particle content and the standard model gauge group. This includes models with gravity mediated supersymmetry breaking, as well as models with anomaly mediated supersymmetry breaking. We include the next-to-leading order corrections in our evaluation of these bounds. We then expand the mass matrix in powers of MZ/μ and find the upper bound on the mass of the lightest neutralino from this expansion. By scanning over all of the parameter space, we find that the bound we have obtained can be saturated. We compare the general upper bound on the lightest neutralino mass to the upper bound that is obtained when the radiative electroweak symmetry breaking scenario is assumed
Constraints on Sparticle Spectrum in different Supersymmetry Breaking Models
We derive sum rules for the sparticle masses in different models of
supersymmetry breaking. This includes the gravity mediated models (SUGRA
models) as well as models in which supersymmetry breaking terms are induced by
super-Weyl anomaly (AMSB models). These sum rules can help in distinguishing
between these models. In particular we obtain an upper bound on the mass of the
lightest neutralino as a function of the gluino mass in SUGRA and AMSB models.Comment: 3 pages, latex, two figures, macros included. Talk presented at IXth
International Symposium on Particles, Strings and Cosmology(PASCOS'03), TIFR,
MUmbai, India, January 3 - 8, 2003. To appear in the proceeding
Phenomenology of non-universal gaugino masses and implications for the Higgs boson decay
Grand unified theories (GUTs) can lead to non-universal gaugino masses at the
unification scale. We study the implications of such non-universal gaugino
masses for the composition of the lightest neutralino in supersymmetric (SUSY)
theories based on SU(5) gauge group. We also consider the phenomenological
implications of non-universal gaugino masses for the phenomenology of Higgs
bosons in the context of Large Hadron Collider.Comment: 4 pages, 8 eps figures, style files included, Talk at LCWS06,
Bangalore, India; typos correcte
Recommended from our members
Completing the adaptive turn: An integrative view of strategy implementation
Based on our review of the past forty years of strategy implementation research, we find that the focus of the research area has moved from the pioneering structural control view to a more adaptive conception of strategy implementation. While early research focused mainly on how to conceptualize strategy implementation plans and how to establish optimal structures, systems, incentives, and controls for strategy implementation, the adaptive turn has shifted the research emphasis on to how organizations make sense of and enact strategies in practice. Although this adaptive turn has contributed significantly to understanding how strategies are implemented and adapted, it has also led to a further fragmentation of the field. We put forward an integrative view that aims at combining the distinctive strengths of the two complementary views. Instead of focusing either on conceptualizing or on enacting, we call for researchers to examine the continuous interplay of conceptualizing and enacting strategies at multiple hierarchical levels and in multiple organizational units simultaneously. We hope that our review will inspire future strategy implementation research to complete the adaptive turn through an enhanced, integrative view of strategy implementation
In Vitro Identification and In Vivo Confirmation of Inhibitors for Sweet Potato Chlorotic Stunt Virus RNA Silencing Suppressor, a Viral RNase III
Sweet potato virus disease (SPVD), caused by synergistic infection of Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato feathery mottle virus (SPFMV), is responsible for substantial yield losses all over the world. However, there are currently no approved treatments for this severe disease. The crucial role played by RNase III of SPCSV (CSR3) as an RNA silencing suppressor during the viruses' synergistic interaction in sweetpotato makes it an ideal drug target for developing antiviral treatment. In this study, high-throughput screening (HTS) of small molecular libraries targeting CSR3 was initiated by a virtual screen using Glide docking, allowing the selection of 6,400 compounds out of 136,353. We subsequently developed and carried out kinetic-based HTS using fluorescence resonance energy transfer technology, which isolated 112 compounds. These compounds were validated with dose-response assays including kinetic-based HTS and binding affinity assays using surface plasmon resonance and microscale thermophoresis. Finally, the interference of the selected compounds with viral accumulation was verified in planta. In summary, we identified five compounds belonging to two structural classes that inhibited CSR3 activity and reduced viral accumulation in plants. These results provide the foundation for developing antiviral agents targeting CSR3 to provide new strategies for controlling sweetpotato virus diseases. IMPORTANCE We report here a high-throughput inhibitor identification method that targets a severe sweetpotato virus disease caused by coinfection with two viruses (SPCSV and SPFMV). The disease is responsible for up to 90% yield losses. Specifically, we targeted the RNase III enzyme encoded by SPCSV, which plays an important role in suppressing the RNA silencing defense system of sweetpotato plants. Based on virtual screening, laboratory assays, and confirmation in planta, we identified five compounds that could be used to develop antiviral drugs to combat the most severe sweetpotato virus disease.Peer reviewe
Dimensionless Coupling of Bulk Scalars at the LHC
We identify the lowest-dimension interaction which is possible between
Standard Model brane fields and bulk scalars in 6 dimensions. The
lowest-dimension interaction is unique and involves a trilinear coupling
between the Standard Model Higgs and the bulk scalar. Because this interaction
has a dimensionless coupling, it depends only logarithmically on ultraviolet
mass scales and heavy physics need not decouple from it. We compute its
influence on Higgs physics at ATLAS and identify how large a coupling can be
detected at the LHC. Besides providing a potentially interesting signal in
Higgs searches, such couplings provide a major observational constraint on 6D
large-extra-dimensional models with scalars in the bulk.Comment: 20 page
Sparticle spectrum and constraints in anomaly mediated supersymmetry breaking models
We study in detail the particle spectrum in anomaly mediated supersymmetry
breaking models in which supersymmetry breaking terms are induced by the
super-Weyl anomaly. We investigate the minimal anomaly mediated supersymmetry
breaking models, gaugino assisted supersymmetry breaking models, as well as
models with additional residual nondecoupling D-term contributions due to an
extra U(1) gauge symmetry at a high energy scale. We derive sum rules for the
sparticle masses in these models which can help in differentiating between
them. We also obtain the sparticle spectrum numerically, and compare and
contrast the results so obtained for the different types of anomaly mediated
supersymmetry breaking models.Comment: LaTeX, 20 pages, 6 figures. A few comments and a reference added;
typos corrected; version published in Phys. Rev.
Higgs and non-universal gaugino masses: no SUSY signal expected yet?
So far, no supersymmetric particles have been detected at the Large Hadron
Collider (LHC). However, the recent Higgs results have interesting implications
for the SUSY parameter space. In this paper, we study the consequences of an
LHC Higgs signal for a model with non-universal gaugino masses in the context
of SU(5) unification. The gaugino mass ratios associated with the higher
representations produce viable spectra that are largely inaccessible to the
current LHC and direct dark matter detection experiments. Thus, in light of the
Higgs results, the non-observation of SUSY is no surprise.Comment: supplementary file containing plots with log priors in ancillary
files. v2: added some comments on more general settings and references,
accepted for publication in JHE
Small-RNA analysis of pre-basic mother plants and conserved accessions of plant genetic resources for the presence of viruses
Pathogen-free stocks of vegetatively propagated plants are crucial in certified plant production. They require regular monitoring of the plant germplasm for pathogens, especially of the stocks maintained in the field. Here we tested pre-basic mother plants of Fragaria, Rubus and Ribes spp., and conserved accessions of the plant genetic resources of Rubus spp. maintained at research stations in Finland, for the presence of viruses using small interfering RNA (siRNA) -based diagnostics (VirusDetect). The advance of the method is that unrelated viruses can be detected simultaneously without resumptions of the viruses present. While no virus was detected in pre-basic mother plants of Fragaria and Ribes species, rubus yellow net virus (RYNV) was detected in pre-basic mother plants of Rubus. Raspberry bushy dwarf virus (RBDV), black raspberry necrosis virus (BRNV), raspberry vein chlorosis virus (RVCV) and RYNV were detected in the Rubus genetic resource collection. The L polymerase encoding sequence characterized from seven RVCV isolates showed considerable genetic variation. The data provide the first molecular biological evidence for the presence of RYNV in Finland. RYNV was not revealed in virus indexing by indicator plants, which suggests that it may be endogenously present in some raspberry cultivars. In addition, a putative new RYNV-like badnavirus was detected in Rubus spp. Blackcurrant reversion virus (BRV) and gooseberry vein banding associated virus (GVBaV) were detected in symptomatic Ribes plants grown in the field. Results were consistent with those obtained using PCR or reverse transcription PCR and suggest that the current virus indexing methods of pre-basic mother plants work as expected. Furthermore, many new viruses were identified in the collections of plant genetic resources not previously tested for viruses. In the future, siRNA-based diagnostics could be a useful supplement for the currently used virus detection methods in certified plant production and thus rationalize and simplify the current testing system.Peer reviewe
- …