401 research outputs found
Finding Higgs bosons heavier than 2 m_W in dileptonic W-boson decays
We reconsider observables for discovering a heavy Higgs boson (with m_h >
2m_W) via its di-leptonic decays h -> WW -> l nu l nu. We show that observables
generalizing the transverse mass that take into account the fact that both of
the intermediate W bosons are likely to be on-shell give a significant
improvement over the variables used in existing searches. We also comment on
the application of these observables to other decays which proceed via
narrow-width intermediates.Comment: v1:4 pages, 1 figure; v2: 6 pages, 2 figures, substantially revise
Controlling Size in Multicellular Organs: Focus on the Leaf
In leaves, cells get larger as cell division decreases or the ploidy increases. This might seem a logical response, but the controls are more complicated
ROTUNDIFOLIA4 Regulates Cell Proliferation Along the Body Axis in Arabidopsis Shoot
Molecular genetics has been successful in identifying leaf- size regulators such as transcription factors, phytohormones, and signal molecules. Among them, a ROTUNDIFOLIA4-LIKE/DEVIL (RTFL/DVL) family of Arabidopsis, genes encoding peptides with no secretion-signal sequence, is unique in that their overexpressors have a reduced number of leaf cells specifically along the proximodistal axis. However, because the RTFL/DVL lack any obvious homology with functionally identified domains, and because of genetic redundancy among RTFL/DVL, their molecular and developmental roles are unclear. In this study we focused on one member in the family, ROTUNDIFOLIA4 (ROT4), and identified the core functional region within it and we found no proteolytic processing in planta. Developmental analysis of leaf primordia revealed that ROT4 overexpression reduces the meristematic zone size within the leaf blade. Moreover, induced local overexpression demonstrated that ROT4 acts as a regulator of the leaf shape via a change in positional cue along the longitudinal axis. Similarly, ROT4 overexpression results in a protrusion of the main inflorescence stem, again indicating a change in positional cue along the longitudinal axis. These results suggest that ROT4 affects the positional cue and cell proliferation along the body axis
Topology and Wilson lines: global aspects of the double copy
The Kerr-Schild double copy relates exact solutions of gauge and gravity
theories. In all previous examples, the gravity solution is associated with an
abelian-like gauge theory object, which linearises the Yang-Mills equations.
This appears to be at odds with the double copy for scattering amplitudes, in
which the non-abelian nature of the gauge theory plays a crucial role.
Furthermore, it is not yet clear whether or not global properties of classical
fields - such as non-trivial topology - can be matched between gauge and
gravity theories. In this paper, we clarify these issues by explicitly
demonstrating how magnetic monopoles associated with arbitrary gauge groups can
be double copied to the same solution (the pure NUT metric) in gravity. We
further describe how to match up topological information on both sides of the
double copy correspondence, independently of the nature of the gauge group.
This information is neatly expressed in terms of Wilson line operators, and we
argue through specific examples that they provide a useful bridge between the
classical double copy and the BCJ double copy for scattering amplitudes.Comment: 31 pages, 4 figures. Some minor corrections have been implemente
Physics at a 100 TeV pp collider: Higgs and EW symmetry breaking studies
This report summarises the physics opportunities for the study of Higgs
bosons and the dynamics of electroweak symmetry breaking at the 100 TeV pp
collider.Comment: 187 pages, 94 figures. Chapter 2 of the "Physics at the FCC-hh"
Repor
Freight Volume Modeling on Major Highway Links
69A3551747109With this research the authors would like to validate the feasibility of freight volume estimation on major highways links from accurate but sparse sensor data, by studying a restricted control area covering approximately 12 square miles around the Ports of Los Angeles and Long Beach where freight volume is most relevant. The authors researched creating a real-world dataset of real-world data in this region, however, due to the COVID 19 pandemic the authors had to limit the collection to publicly available Caltrans CCTV video footage and leveraged the authors' ADMS traffic database to generate synthetic data. The authors have implemented state-of-the-art computer vision algorithms, which were used to classify trucks and define truck categories optimized for best performance. These results show that it is feasible to use CCTV cameras to detect and classify trucks and that the process can be fully automated. In parallel, the authors created a truck simulator to generate realistic truck trajectories between predefined locations, and developed algorithms to estimate freight on links with different heuristics. The authors' approach provides the best results by relating compatible observations across sensors using travel-time information estimated on current traffic conditions. The authors' preliminary results show that freight volume estimation on major highways links is feasible
Electroweak Symmetry Breaking at the LHC
One of the major goals of the Large Hadron Collider is to probe the
electroweak symmetry breaking mechanism and the generation of the masses of the
elementary particles. We review the physics of the Higgs sector in the Standard
Model and some of its extensions such as supersymmetric theories and models of
extra dimensions. The prospects for discovering the Higgs particles at the LHC
and the study of their fundamental properties are summarised.Comment: 27 pages, 45 figures, uses LaTeX (insa.sty). Invited review for
volume on LHC physics to celebrate the Platinum Jubilee of the Indian
National Science Academy, edited by Amitava Datta, Biswarup Mukhopadhyaya and
Amitava Raychaudhuri. Expanded the acronym in the title in the annoncement.
No other change in the text or reference
The Weyl double copy from twistor space
The Weyl double copy is a procedure for relating exact solutions in biadjoint scalar, gauge and gravity theories, and relates fields in spacetime directly. Where this procedure comes from, and how general it is, have until recently remained mysterious. In this paper, we show how the current form and scope of the Weyl double copy can be derived from a certain procedure in twistor space. The new formalism shows that the Weyl double copy is more general than previously thought, applying in particular to gravity solutions with arbitrary Petrov types. We comment on how to obtain anti-self-dual as well as self-dual fields, and clarify some conceptual issues in the twistor approach
NMSSM Higgs Benchmarks Near 125 GeV
The recent LHC indications of a SM-like Higgs boson near 125 GeV are
consistent not only with the Standard Model (SM) but also with Supersymmetry
(SUSY). However naturalness arguments disfavour the Minimal Supersymmetric
Standard Model (MSSM). We consider the Next-to-Minimal Supersymmetric Standard
Model (NMSSM) with a SM-like Higgs boson near 125 GeV involving relatively
light stops and gluinos below 1 TeV in order to satisfy naturalness
requirements. We are careful to ensure that the chosen values of couplings do
not become non perturbative below the grand unification (GUT) scale, although
we also examine how these limits may be extended by the addition of extra
matter to the NMSSM at the two-loop level. We then propose four sets of
benchmark points corresponding to the SM-like Higgs boson being the lightest or
the second lightest Higgs state in the NMSSM or the NMSSM-with-extra-matter.
With the aid of these benchmark points we discuss how the NMSSM Higgs boson
near 125 GeV may be distinguished from the SM Higgs boson in future LHC
searches.Comment: 40 pages, 1 figure; Minor changes and further references include
Performance analysis of existing catfish and tilapia value chains and market systems in Nigeria: A post-farmgate value chain scoping study
Nigeria is the largest fish producer in Sub-Saharan Africa. Fish plays a crucial role in supporting the
livelihoods of fish producers and actors along the post-farmgate value chain in the country. Despite the
virtues of the aquaculture and fisheries subsectors to enhance the livelihoods of value chain actors, major
gaps exist related to efficiencies of the fish value chain. These gaps include the financial performance of
post-farmgate actors, gender-disaggregated data on value chain actors, the roles of women and youths
in fish trade, and post-farmgate food safety practices. The aim of this study is to fill the data gap in the
post-farmgate fish value chain to provide evidence-based policy suggestions to enhance the aquaculture
subsector in Nigeria. Using primary data, our study provides evidence on the economic, environmental,
social, nutritional and food safety performance of the post-farmgate fish value chain. Our study finds that,
in general, fish value chains are economically viable (profitable) and inclusive, as women and youths own
over half of post-farmgate value chain activities. These results are of interest to both private and public
sector decision-makers and policymakers because they provide quantitative data on value creation
(fish sales, employment, service provision), social performance (women and youth empowerment), and
environmental, nutritional and food safety challenges along fish value chains
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