25,896 research outputs found
Kaluza-Klein Gluons as a Diagnostic of Warped Models
We study the properties of , the first excited state of the gluon in
representative variants of the Randall Sundrum model with the Standard Model
fields in the bulk. We find that measurements of the coupling to light quarks
(from the inclusive cross-section for ), the coupling
to bottom quarks (from the rate of ), as well as the overall
width, can provide powerful discriminants between the models. In models with
large brane kinetic terms, the resonance can even potentially be
discovered decaying into dijets against the large QCD background. We also
derive bounds based on existing Tevatron searches for resonant
production and find that they require GeV. In addition
we explore the pattern of interference between the signal and the
non-resonant SM background, defining an asymmetry parameter for the invariant
mass distribution. The interference probes the relative signs of the couplings
of the to light quark pairs and to , and thus provides an
indication that the top is localized on the other side of the extra dimension
from the light quarks, as is typical in the RS framework.Comment: 25 pages, 10 figure
Entanglement Spectra of the quantum hard-square model: Holographic minimal models
We study the entanglement properties of a quantum lattice-gas model for which
we can find the exact ground state (of the Rokhsar-Kivelson type). The ground
state can be expressed as a superposition of states, each of which is
characterized by a particle configuration with nearest-neighbor exclusion. We
show that the reduced density matrix of the model on a ladder is intimately
related to the transfer matrix of the classical hard-square model. The
entanglement spectra of the model on square and triangular ladders are critical
when parameters are chosen so that the corresponding classical hard-square
models are critical. A detailed analysis reveals that the critical theories for
the entanglement Hamiltonians are minimal conformal field theories. We
further show that the entanglement Hamiltonian for the triangular ladder is
integrable despite the fact that the original quantum lattice-gas model is
non-integrable.Comment: 10 pages, 8 figure
The Nutrition Transition in High and Low-Income Countries: What are the Policy Lessons?
The world has seen a remarkable shift from a period when diets, activity patterns and body composition were characterized by the period termed the receding famine pattern to one dominated by nutrition-related non-communicable diseases (NR-NCDs). This presentation first examines the speed of these changes, summarizes dietary changes, and provides some sense of the way the burden of obesity is shifting from the rich to the poor not only in urban but also rural areas throughout the world. The focus is on the lower- and middle- income countries of Asia, Africa, the Middle East, and Latin America but some examples will come from the United States, Australia, and the UK. After showing that changes are occurring at great speed and at earlier stages of countries' economic and social development, the presentation shifts to some of the critical policy opportunities and some example of options. Few policy lessons exist at a macro level outside of selected countries such as South Korea and Finland. Examples of ways price policy and other options might work, using Chinese longitudinal case studies, are presented. The challenge is for the agricultural economics profession to focus on this major global issue-one which challenges some of the earlier paradigms of food policy an agricultural development.diet composition, price policy, economic growth, health effects, Food Consumption/Nutrition/Food Safety,
Computer program documentation for a subcritical wing design code using higher order far-field drag minimization
A subsonic, linearized aerodynamic theory, wing design program for one or two planforms was developed which uses a vortex lattice near field model and a higher order panel method in the far field. The theoretical development of the wake model and its implementation in the vortex lattice design code are summarized and sample results are given. Detailed program usage instructions, sample input and output data, and a program listing are presented in the Appendixes. The far field wake model assumes a wake vortex sheet whose strength varies piecewise linearly in the spanwise direction. From this model analytical expressions for lift coefficient, induced drag coefficient, pitching moment coefficient, and bending moment coefficient were developed. From these relationships a direct optimization scheme is used to determine the optimum wake vorticity distribution for minimum induced drag, subject to constraints on lift, and pitching or bending moment. Integration spanwise yields the bound circulation, which is interpolated in the near field vortex lattice to obtain the design camber surface(s)
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