5,977 research outputs found
Universality of weakly bound dimers and Efimov trimers close to Li-Cs Feshbach resonances
We study the interspecies scattering properties of ultracold Li-Cs mixtures
in their two energetically lowest spin channels in the magnetic field range
between 800 G and 1000 G. Close to two broad Feshbach resonances we create
weakly bound LiCs dimers by radio-frequency association and measure the
dependence of the binding energy on the external magnetic field strength. Based
on the binding energies and complementary atom loss spectroscopy of three other
Li-Cs s-wave Feshbach resonances we construct precise molecular singlet and
triplet electronic ground state potentials using a coupled-channels
calculation. We extract the Li-Cs interspecies scattering length as a function
of the external field and obtain almost a ten-fold improvement in the precision
of the values for the pole positions and widths of the s-wave Li-Cs Feshbach
resonances as compared to our previous work [Pires \textit{et al.}, Phys. Rev.
Lett. \textbf{112}, 250404 (2014)]. We discuss implications on the Efimov
scenario and the universal geometric scaling for LiCsCs trimers
Five-Dimensional QED, Muon Pair Production and Correction to the Coulomb Potential
We consider QED in five dimensions in a configuration where matter is
localized on a 3-brane while foton propagates in the bulk. The idea is to
investigate the effects of the Kaluza-Klein modes of the photon in the
relativistic regime, but in low energy, and in the nonrelativistic regime. In
the relativistic regime, we calculate the cross section for the reaction . We compare our theoretical result with a precise
measurement of this cross section at GeV. As result, we
extract a lower bound on the size of the extra dimension. In the
nonrelativistic regime, we derive the contribution for the Coulomb potential
due to the whole tower of the Kaluza-Klein excited modes of the photon. We use
the modified potential to calculate the Rutherford scattering differential
cross section.Comment: minor changes, three new refs. added, to appear in IJMP
Universal three-body recombination and Efimov resonances in an ultracold Li-Cs mixture
We study Efimov resonances via three-body loss in an ultracold two-component
gas of fermionic Li and bosonic Cs atoms close to a Feshbach
resonance at 843~G, extending results reported previously [Pires \textit{et
al.}, Phys. Rev. Lett. 112, 250404 (2014)] to temperatures around 120~nK. The
experimental scheme for reaching lower temperatures is based upon compensating
the gravity-induced spatial separation of the mass-imbalanced gases with
bichromatic optical dipole traps. We observe the first and second excited
Li-Cs-Cs Efimov resonance in the magnetic field dependence of the three-body
event rate constant, in good agreement with the universal zero-range theory at
finite temperature [Petrov and Werner, Phys. Rev. A 92, 022704 (2015)].
Deviations are found for the Efimov ground state, and the inelasticity
parameter is found to be significantly larger than those for
single-species systems
Pollination efficiency of P. juliflora (SW) DC in Petrolina, Pernambuco.
This research study aims, therefore, at defining the reproductive sysrern and the possible causes for the low fruit output per inflorescence, i.e. the low pollination efficiency
Cork biomass biocomposites: lightweight and sustainable materials
Chapter 17. Cork biomass biocomposites: lightweight and sustainable materials.The authors would like to thank to the financial support from the Portuguese Foundation for Science
and Technology (FCT) for the fellowship grant of Emanuel M. Fernandes (SFRH/BPD/96197/2013),
“Fundo Social Europeu”- FSE and “Programa Diferencial de Potencial Humano POPH”.info:eu-repo/semantics/publishedVersio
On the width of the last scattering surface
We discuss the physical effects of some accelerated world models on the width
of the last scattering surface (LSS) of the cosmic microwave background
radiation (CMBR). The models considered in our analysis are X-matter (XCDM) and
a Chaplygin type gas. The redshift of the LSS does not depend on the kind of
dark energy (if XCDM of Chaplygin). Further, for a Chaplygin gas, the width of
the LSS is also only weakly dependent on the kind of scenario (if we have dark
energy plus cold dark matter or the unified picture).Comment: 10 pages, 1 figure, 2 tables, accepted to IJMP
Zoom-in-Net: Deep Mining Lesions for Diabetic Retinopathy Detection
We propose a convolution neural network based algorithm for simultaneously
diagnosing diabetic retinopathy and highlighting suspicious regions. Our
contributions are two folds: 1) a network termed Zoom-in-Net which mimics the
zoom-in process of a clinician to examine the retinal images. Trained with only
image-level supervisions, Zoomin-Net can generate attention maps which
highlight suspicious regions, and predicts the disease level accurately based
on both the whole image and its high resolution suspicious patches. 2) Only
four bounding boxes generated from the automatically learned attention maps are
enough to cover 80% of the lesions labeled by an experienced ophthalmologist,
which shows good localization ability of the attention maps. By clustering
features at high response locations on the attention maps, we discover
meaningful clusters which contain potential lesions in diabetic retinopathy.
Experiments show that our algorithm outperform the state-of-the-art methods on
two datasets, EyePACS and Messidor.Comment: accepted by MICCAI 201
- …