3,534 research outputs found
Higgs boson production via vector-like top-partner decays: diphoton or multilepton plus multijets channels at the LHC
We first build a minimal model of vector-like quarks where the dominant Higgs
boson production process at LHC -- the gluon fusion -- can be significantly
suppressed, being motivated by the recent stringent constraints from the search
for direct Higgs production over a wide Higgs mass range. Within this model,
compatible with the present experimental constraints on direct Higgs searches,
we demonstrate that the Higgs () production via a heavy vector-like
top-partner () decay, , , allows to
discover a Higgs boson at the LHC and measure its mass, through the decay
channels or . We also comment on the recent hint
in LHC data from a possible GeV Higgs scalar, in the presence of
heavy vector-like top quarks.Comment: 14 pages, 8 figure
Constraints on supersymmetry with light third family from LHC data
We present a re-interpretation of the recent ATLAS limits on supersymmetry in
channels with jets (with and without b-tags) and missing energy, in the context
of light third family squarks, while the first two squark families are
inaccessible at the 7 TeV run of the Large Hadron Collider (LHC). In contrast
to interpretations in terms of the high-scale based constrained minimal
supersymmetric standard model (CMSSM), we primarily use the low-scale
parametrisation of the phenomenological MSSM (pMSSM), and translate the limits
in terms of physical masses of the third family squarks. Side by side, we also
investigate the limits in terms of high-scale scalar non-universality, both
with and without low-mass sleptons. Our conclusion is that the limits based on
0-lepton channels are not altered by the mass-scale of sleptons, and can be
considered more or less model-independent.Comment: 20 pages, 8 figures, 2 tables. Version published in JHE
An early warning method for agricultural products price spike based on artificial neural networks prediction
In general, the agricultural producing sector is affected by the diversity in supply, mostly from small companies, in addition to the rigidity of the demand, the territorial dispersion, the seasonality or the generation of employment related to the rural environment. These characteristics differentiate the agricultural sector from other economic sectors. On the other hand, the volatility of prices payed by producers, the high cost of raw materials, and the instability of both domestic and international markets are factors which have eroded the competitiveness and profitability of the agricultural sector. Because of the advance in technology, applications have been developed based on Artificial Neural Networks (ANN) which have helped the development of sales forecast on consumer products, improving the accuracy of traditional forecasting systems. This research uses the RNA to develop an early warning system for facing the increase in agricultural products, considering macro and micro economic variables and factors related to the seasons of the year
Where is SUSY?
The direct searches for Superymmetry at colliders can be complemented by
direct searches for dark matter (DM) in underground experiments, if one assumes
the Lightest Supersymmetric Particle (LSP) provides the dark matter of the
universe. It will be shown that within the Constrained minimal Supersymmetric
Model (CMSSM) the direct searches for DM are complementary to direct LHC
searches for SUSY and Higgs particles using analytical formulae. A combined
excluded region from LHC, WMAP and XENON100 will be provided, showing that
within the CMSSM gluinos below 1 TeV and LSP masses below 160 GeV are excluded
(m_{1/2} > 400 GeV) independent of the squark masses.Comment: 16 pages, 10 figure
New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group
We present a collection of signatures for physics beyond the standard model
that need to be explored at the LHC. First, are presented various tools
developed to measure new particle masses in scenarios where all decays include
an unobservable particle. Second, various aspects of supersymmetric models are
discussed. Third, some signatures of models of strong electroweak symmetry are
discussed. In the fourth part, a special attention is devoted to high mass
resonances, as the ones appearing in models with warped extra dimensions.
Finally, prospects for models with a hidden sector/valley are presented. Our
report, which includes brief experimental and theoretical reviews as well as
original results, summarizes the activities of the "New Physics" working group
for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June,
2009).Comment: 189 page
Les Houches 2015: Physics at TeV colliders - new physics working group report
We present the activities of the 'New Physics' working group for the 'Physics
at TeV Colliders' workshop (Les Houches, France, 1-19 June, 2015). Our report
includes new physics studies connected with the Higgs boson and its properties,
direct search strategies, reinterpretation of the LHC results in the building
of viable models and new computational tool developments. Important signatures
for searches for natural new physics at the LHC and new assessments of the
interplay between direct dark matter searches and the LHC are also considered.Comment: Proceedings of the New Physics Working Group of the 2015 Les Houches
Workshop, Physics at TeV Colliders, Les Houches 1-19 June 2015. 197 page
MFV Reductions of MSSM Parameter Space
The 100+ free parameters of the minimal supersymmetric standard model (MSSM)
make it computationally difficult to compare systematically with data,
motivating the study of specific parameter reductions such as the cMSSM and
pMSSM. Here we instead study the reductions of parameter space implied by using
minimal flavour violation (MFV) to organise the R-parity conserving MSSM, with
a view towards systematically building in constraints on flavour-violating
physics. Within this framework the space of parameters is reduced by expanding
soft supersymmetry-breaking terms in powers of the Cabibbo angle, leading to a
24-, 30- or 42-parameter framework (which we call MSSM-24, MSSM-30, and MSSM-42
respectively), depending on the order kept in the expansion. We provide a
Bayesian global fit to data of the MSSM-30 parameter set to show that this is
manageable with current tools. We compare the MFV reductions to the
19-parameter pMSSM choice and show that the pMSSM is not contained as a subset.
The MSSM-30 analysis favours a relatively lighter TeV-scale pseudoscalar Higgs
boson and with multi-TeV sparticles.Comment: 2nd version, minor comments and references added, accepted for
publication in JHE
Deciphering Drought Response Mechanisms: Transcriptomic Insights from Drought-Tolerant and Drought-Sensitive Wheat (Triticum aestivum L.) Cultivars
Drought stress poses a significant threat to wheat (Triticum aestivum L.) cultivation, necessitating an in-depth understanding of the molecular mechanisms underpinning drought response in both tolerant and sensitive varieties. In this study, 12 diverse bread wheat cultivars were evaluated for their drought stress responses, with particular emphasis on the contrasting performance of cultivars Atay 85 (sensitive), Gerek 79, and Mufitbey (tolerant). Transcriptomic analysis was performed on the root and leaf tissues of the aforementioned cultivars subjected to 4-hour and 8-hour drought stress and compared with controls. Differentially expressed genes (DEGs) were categorized based on their cellular component, molecular function, and biological function. Notably, there was greater gene expression variability in leaf tissues compared to root tissues. A noticeable trend of decreased gene expression was observed for cellular processes such as protein refolding and cellular metabolic processes like photorespiration as drought stress duration increased (8 hours) in the leaf tissues of drought-tolerant and sensitive cultivars. Metabolic processes related to gene expression were predominantly activated in response to 4-hour and 8-hour drought stress. The drought-tolerant cultivars exhibited increased expression levels of genes related to protein binding, metabolic processes, and cellular functions, indicating their ability to adapt better to drought stress compared to the drought-sensitive cultivar Atay 85. We detected more than 25 differentially expressed TFs in leaf tissues under 4-hour and 8-hour drought stress, while only 4 TFs were identified in the root tissues of sensitive cultivar. In contrast, the tolerant cultivar exhibited more than 80 different TF transcripts in both leaves and roots after 4 hours of drought stress, with this number decreasing to 18 after 8 hours of drought stress. Differentially expressed genes with a focus on metal ion binding, carbohydrate degradation, ABA-related genes, and cell wall-related genes were highlighted. Ferritin (TaFer), TaPME42 and Extensin-like protein (TaExLP), Germin-like protein (TaGLP 9-1), Metacaspase-5 (TaMC5), Arogenate Dehydratase 5 (ADT-5), Phosphoglycerate/ bisphosphoglycerate mutase (TaPGM), Serine/threonine protein phosphatase 2A (TaPP2A), GIGANTEA (TaGI), Polyadenylate-binding protein (TaRBP45B) exhibited differential expression by qRT-PCR in root and leaf tissues of tolerant and sensitive bread wheat cultivars. This study provides valuable insights into the complex molecular mechanisms associated with drought response in wheat, highlighting genes and pathways involved in drought tolerance. Understanding these mechanisms is essential for developing drought-tolerant wheat varieties, enhancing agricultural sustainability, and addressing the challenges posed by water scarcity
Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons
We report measurements of the resonance properties of Lambda_c(2595)+ and
Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as
Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+
pi+/- final states. These measurements are performed using data corresponding
to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV,
collected with the CDF II detector at the Fermilab Tevatron. Exploiting the
largest available charmed baryon sample, we measure masses and decay widths
with uncertainties comparable to the world averages for Sigma_c states, and
significantly smaller uncertainties than the world averages for excited
Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17
pages, 15 figure
Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for a new heavy charged vector boson decaying
to an electron-neutrino pair in collisions at a center-of-mass
energy of 1.96\unit{TeV}. The data were collected with the CDF II detector
and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No
significant excess above the standard model expectation is observed and we set
upper limits on . Assuming standard
model couplings to fermions and the neutrino from the boson decay to
be light, we exclude a boson with mass less than
1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR
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