166,437 research outputs found
Cross sections for pentaquark baryon production from protons in reactions induced by hadrons and photons
Using hadronic Lagrangians that include the interaction of pentaquark
baryon with and , we evaluate the cross sections for its
production from meson-proton, proton-proton, and photon-proton reactions near
threshold. With empirical coupling constants and form factors, the predicted
cross sections are about 1.5 mb in kaon-proton reactions, 0.1 mb in rho-nucleon
reactions, 0.05 mb in pion-nucleon reactions, 20 b in proton-proton
reactions, and 40 nb in photon-proton reactions.Comment: 14 pages, 7 figure
Mass in anti-de Sitter spaces
The boundary stress tensor approach has proven extremely useful in defining
mass and angular momentum in asymptotically anti-de Sitter spaces with CFT
duals. An integral part of this method is the use of boundary counterterms to
regulate the gravitational action and stress tensor. In addition to the
standard gravitational counterterms, in the presence of matter we advocate the
use of a finite counterterm proportional to phi^2 (in five dimensions). We
demonstrate that this finite shift is necessary to properly reproduce the
expected mass/charge relation for R-charged black holes in AdS_5.Comment: 15 pages, late
Quantum Statistical Entropy and Minimal Length of 5D Ricci-flat Black String with Generalized Uncertainty Principle
In this paper, we study the quantum statistical entropy in a 5D Ricci-flat
black string solution, which contains a 4D Schwarzschild-de Sitter black hole
on the brane, by using the improved thin-layer method with the generalized
uncertainty principle. The entropy is the linear sum of the areas of the event
horizon and the cosmological horizon without any cut-off and any constraint on
the bulk's configuration rather than the usual uncertainty principle. The
system's density of state and free energy are convergent in the neighborhood of
horizon. The small-mass approximation is determined by the asymptotic behavior
of metric function near horizons. Meanwhile, we obtain the minimal length of
the position which is restrained by the surface gravities and the
thickness of layer near horizons.Comment: 11pages and this work is dedicated to the memory of Professor Hongya
Li
A mathematical simulation model of the CH-47B helicopter, volume 1
A nonlinear simulation model of the CH-47B helicopter was adapted for use in the NASA Ames Research Center (ARC) simulation facility. The model represents the specific configuration of the ARC variable stability CH-47B helicopter and will be used in ground simulation research and to expedite and verify flight experiment design. Modeling of the helicopter uses a total force approach in six rigid body degrees of freedom. Rotor dynamics are simulated using the Wheatlely-Bailey equations including steady-state flapping dynamics. Also included in the model is the option for simulation of external suspension, slung-load equations of motion
Exchange Field-Mediated Magnetoresistance in the Correlated Insulator Phase of Be Films
We present a study of the proximity effect between a ferromagnet and a
paramagnetic metal of varying disorder. Thin beryllium films are deposited onto
a 5 nm-thick layer of the ferromagnetic insulator EuS. This bilayer arrangement
induces an exchange field, , of a few tesla in low resistance Be films
with sheet resistance , where is the quantum resistance.
We show that survives in very high resistance films and, in fact,
appears to be relatively insensitive to the Be disorder. We exploit this fact
to produce a giant low-field magnetoresistance in the correlated insulator
phase of Be films with .Comment: To be published in Physical Review Letter
LoANs: Weakly Supervised Object Detection with Localizer Assessor Networks
Recently, deep neural networks have achieved remarkable performance on the
task of object detection and recognition. The reason for this success is mainly
grounded in the availability of large scale, fully annotated datasets, but the
creation of such a dataset is a complicated and costly task. In this paper, we
propose a novel method for weakly supervised object detection that simplifies
the process of gathering data for training an object detector. We train an
ensemble of two models that work together in a student-teacher fashion. Our
student (localizer) is a model that learns to localize an object, the teacher
(assessor) assesses the quality of the localization and provides feedback to
the student. The student uses this feedback to learn how to localize objects
and is thus entirely supervised by the teacher, as we are using no labels for
training the localizer. In our experiments, we show that our model is very
robust to noise and reaches competitive performance compared to a
state-of-the-art fully supervised approach. We also show the simplicity of
creating a new dataset, based on a few videos (e.g. downloaded from YouTube)
and artificially generated data.Comment: To appear in AMV18. Code, datasets and models available at
https://github.com/Bartzi/loan
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