Isoscalar electric multipole strength in C-12

Journals published by the American Physical Society can be found at http://publish.aps.org/The excitation region in C-12 below E-x=45 MeV was studied using 240 MeV alpha-particle scattering. Elastic scattering was measured from theta(c.m.)=3.8degrees to 49.4degrees and density dependant folding optical model parameters were obtained. Inelastic scattering to the 4.44 MeV 2(+), 7.65 MeV 0(+), 9.64 MeV 3(-), 10.3 MeV 0(+), and 10.84 MeV 1(-) states was measured and B(EL) values obtained. Inelastic scattering exciting C-12 to 10 MeVless than or equal toE(x)less than or equal to12.5 MeV was measured from 1.4degreesless than or equal totheta(c.m.)less than or equal to10degrees and to 12.5 MeVless than or equal toE(x)less than or equal to45 MeV from 1.4degreesless than or equal totheta(c.m.)less than or equal to16degrees and E0, E1, E2, and E3 strength distributions were obtained. Strength was identified corresponding to 27+/-5, 78+/-9, and 51+/-7% of the isoscalar E0, E1, and E2 energy weighted sum rule (EWSR), respectively, with centroids of 21.9+/-0.3, 27.5+/-0.4, and 22.6+/-0.5 MeV and rms widths of 4.8+/-0.5, 7.6+/-0.6, and 6.8+/-0.6 MeV. Less than 7% of the E3 EWSR strength was identified

Numerical studies of the fractional quantum Hall effect in systems with tunable interactions

The discovery of the fractional quantum Hall effect in GaAs-based semiconductor devices has lead to new advances in condensed matter physics, in particular the possibility for exotic, topological phases of matter that possess fractional, and even non-Abelian, statistics of quasiparticles. One of the main limitations of the experimental systems based on GaAs has been the lack of tunability of the effective interactions between two-dimensional electrons, which made it difficult to stabilize some of the more fragile states, or induce phase transitions in a controlled manner. Here we review the recent studies that have explored the effects of tunability of the interactions offered by alternative two-dimensional systems, characterized by non-trivial Berry phases and including graphene, bilayer graphene and topological insulators. The tunability in these systems is achieved via external fields that change the mass gap, or by screening via dielectric plate in the vicinity of the device. Our study points to a number of different ways to manipulate the effective interactions, and engineer phase transitions between quantum Hall liquids and compressible states in a controlled manner.Comment: 9 pages, 4 figures, updated references; review for the CCP2011 conference, to appear in "Journal of Physics: Conference Series

SHREC'16 Track: 3D Sketch-Based 3D Shape Retrieval

Sketch-based 3D shape retrieval has unique representation availability of the queries and vast applications. Therefore, it has received more and more attentions in the research community of content-based 3D object retrieval. However, sketch-based 3D shape retrieval is a challenging research topic due to the semantic gap existing between the inaccurate representation of sketches and accurate representation of 3D models. In order to enrich and advance the study of sketch-based 3D shape retrieval, we initialize the research on 3D sketch-based 3D model retrieval and collect a 3D sketch dataset based on a developed 3D sketching interface which facilitates us to draw 3D sketches in the air while standing in front of a Microsoft Kinect. The objective of this track is to evaluate the performance of different 3D sketch-based 3D model retrieval algorithms using the hand-drawn 3D sketch query dataset and a generic 3D model target dataset. The benchmark contains 300 sketches that are evenly divided into 30 classes, as well as 1 258 3D models that are classified into 90 classes. In this track, nine runs have been submitted by five groups and their retrieval performance has been evaluated using seven commonly used retrieval performance metrics. We wish this benchmark, the comparative evaluation results and the corresponding evaluation code will further promote sketch-based 3D shape retrieval and its applications

Isoscalar giant resonances for nuclei with mass between 56 and 60

Journals published by the American Physical Society can be found at http://publish.aps.org/The giant resonance region from 10 MeV < E-x < 62 MeV in Fe-56, Ni-58, and Ni-60 has been studied with inelastic scattering of 240 MeV alpha particles at small angles, including 0 degrees. Most of the expected isoscalar E0 and E2 strength has been identified below E-x = 40 MeV. Between 56 and 72% of the isoscalar E1 strength has been located in these nuclei. The mass dependence of the giant monopole energy between A = 40 and 90 is compared to relativistic and nonrelativistic calculations for interactions with compressibility of nuclear matter K-NM similar to 211-225 MeV

Isoscalar E0 strength between 6 and 11 MeV in Ca-40

Journals published by the American Physical Society can be found at http://publish.aps.org/The region from 6<E-x<11 MeV in Ca-40 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0degrees . Strength corresponding to 3.2+/-1.0% of the isoscalar E0 sum rule was identified with a centroid of 8.7+/-0.30 MeV

A sandpile model with tokamak-like enhanced confinement phenomenology

Confinement phenomenology characteristic of magnetically confined plasmas emerges naturally from a simple sandpile algorithm when the parameter controlling redistribution scalelength is varied. Close analogues are found for enhanced confinement, edge pedestals, and edge localised modes (ELMs), and for the qualitative correlations between them. These results suggest that tokamak observations of avalanching transport are deeply linked to the existence of enhanced confinement and ELMs.Comment: Manuscript is revtex (latex) 1 file, 7 postscript figures Revised version is final version accepted for publication in PRL Revisions are mino

The Static and Dynamic Lattice Changes Induced by Hydrogen Adsorption on NiAl(110)

Static and dynamic changes induced by adsorption of atomic hydrogen on the NiAl(110) lattice at 130 K have been examined as a function of adsorbate coverage. Adsorbed hydrogen exists in three distinct phases. At low coverages the hydrogen is itinerant because of quantum tunneling between sites and exhibits no observable vibrational modes. Between 0.4 ML and 0.6 ML, substrate mediated interactions produce an ordered superstructure with c(2x2) symmetry, and at higher coverages, hydrogen exists as a disordered lattice gas. This picture of how hydrogen interacts with NiAl(110) is developed from our data and compared to current theoretical predictions.Comment: 36 pages, including 12 figures, 2 tables and 58 reference