Production of the X( 3872) in B-meson decay by the coalescence of charm mesons

If the recently discovered charmonium state X( 3872) is a loosely bound S-wave molecule of the charm mesons D0 D(*0) or D(*0) D0, it can be produced in B-meson decay by the coalescence of charm mesons. If this coalescence mechanism dominates, the ratio of the differential rate for B+ -->D(0) D(* 0)K+ near the D0 D(*0) threshold and the rate for B+ -->XK+ is a function of the D0 D(*0) invariant mass and hadron masses only. The identification of the X( 3872) as a D0 D(*0)/D(*0)D0 molecule can be confirmed by observing an enhancement in the D0 D(*0) invariant mass distribution near the threshold. An estimate of the branching fraction for B+ -->XK+ is consistent with observations if X has quantum numbers J(PC)=1(++ ) and if J/psi pi(+) pi(-) is one of its major decay modes.     

Study of B-->D(*)sJ +-D(*) decays

We report a study of D(*)(sJ)(2317)(+) and D(sJ)(2460)(+) meson production in B decays. We observe the decays B+-->D((*)+)(sJ)D ((*)0) and B0-->D((*)+)(sJ)D((*)-) with the subsequent decays D(*)(sJ)(2317)(+)-->D(+)(s)pi(0), D(sJ)(2460)(+)-->D(+)(s)gamma, and D(sJ)(2460)(+)-->D(*+)(s)pi(0). Based on a data sample of 122.1 x 10(6) BB pairs collected with the BABAR detector at the PEP-II B factory, we obtain branching fractions for these modes, including the previously unseen decays B-->D((*)+)(sJ)D(*). In addition, we perform an angular analysis of D(sJ)(2460)(+)-->D(+)(s)gamma decays to test the different D(sJ)(2460)(+) spin hypotheses.     

Data page reconstruction method based on two-dimensional soft output Viterbi algorithm with self reference for holographic data storage

This study introduces a two-dimensional (2D) partial response maximum likelihood (PRML) method to reconstruct a degraded data page having 2D inter-symbol interference for holographic data storage. The proposed 2D PRML method consists of 2D partial response (PR) target, 2D equalizer using least mean square algorithm, and 2D soft output Viterbi algorithm (SOVA) having just two one-dimensional (1D) SOVAs in horizontal and vertical directions. To accurately organize a trellis diagram of the 1D SOVA in structural accordance with the 2D PR target, this study proposes the self-reference process for the extrinsic information in the 1D SOVA. Finally, simulation results show that the proposed method has bit error rate performance similar to that of modified 2D SOVA having four 1D SOVAs despite the relatively low computational complexity. Moreover, parallel processing is possible in the two 1D SOVAs through the self-reference process.     

Clock shift in a strongly interacting two-dimensional Fermi gas

We derive universal relations for the rf spectroscopy of a two-dimensional Fermi gas consisting of two spin states interacting through an S-wave scattering length. The rf transition rate has a high-frequency tail that is proportional to the contact and displays logarithmic scaling violations, decreasing asymptotically like 1/(ω2ln2ω). Its coefficient is proportional to ln2'(a'(2D)/a(2D)), where a(2D) and a'(2D) are the two-dimensional scattering lengths associated with initial-state and final-state interactions. The clock shift is proportional to the contact and to ln(a'(2D)/a(2D)). If |ln(a'(2D)/a(2D))| > 1, the clock shift arises as a cancellation between much larger contributions proportional to ln2(a'(2D)/a(2D)) from bound-bound and bound-free rf transitions.     

Carrier cooling and recombination heating in intermixed GaAs/AlGaAs quantum wires and dots

Il Nuovo Cimento D - The cooling of photoexcited hot carriers in 2D, 1D and 0D systems is studied experimentally. In comparison with a theoretical carrier relaxation model which holds for 2D and 1D...     

3D harnessing of light with 2.5D photonic crystals

It is emphasized that two‐dimensional photonic crystals (2D PC) have not only a great potential for the development of 2D nanophotonics in the inplane waveguided configuration, but that they may also open the way to other brilliant developments, with an extension to out‐of‐plane operation, along a 2.5D nanophotonics approach. In this 2.5D approach, a 1D–2D high index contrast lateral structuration is combined with a 1D high index contrast vertical structuration, using multilayer membrane stacks including 1D–2D photonic crystal membranes, thus resulting in so‐called 2.5D PC. As a specific illustration of recent achievements along this approach, new families of VCSEL structures are presented.     

Deconfinement in a 2D optical lattice of coupled 1D boson systems

We show that a two-dimensional (2D) array of 1D interacting boson tubes has a deconfinement transition between a 1D Mott insulator and a 3D superfluid for commensurate fillings and a dimensional crossover for the incommensurate case. We determine the phase diagram and excitations of this system and discuss the consequences for Bose condensates loaded in 2D optical lattices.     

非三维空间的经典气体模型

类似于三维空间中的方法，推导了一、二、四维空间中经典气体的气体动理论的相应的公式和常数，与三维空间的情况做了比较。     

平面三维显示技术的研究现状

平面三维显示技术是近年来最新出现的虚拟现实显示技术,其最大的特点是观察者无需使用任何辅助附加设备,直接用肉眼就可看到屏幕上显示的三维图像。为推进三维显示技术的发展,进一步研究了视差立体成像原理,并据此介绍几种平面三维显示方法及其工作原理,包括障栅立体显示、微柱透镜阵列立体显示、偏振片立体显示和基于微柱透镜立体显示原理的多视点系统,阐述并分析了系统的优缺点。以日本三洋公司的四视角立体显示装置、南京大学的多视点三维显示系统和NEC液晶科技的HDDP三维显示系统为例,描述了国内外该项技术近期的研究现状,分析了存在的技术难点,展望了该应用领域的发展前景。     

Three-dimensional polarimetric integral imaging

A three-dimensional (3D) polarimetric image sensing and display technique based on integral imaging is proposed. Three-dimensional polarization distribution of reflected light from a 3D object can be measured as elemental image arrays by a rotating linear polarizer. After the measurement of the polarization of the 3D object, the 3D polarimetric object can be reconstructed optically by displaying the polarization-selected elemental images in spatial light modulators with two quarter-wave plates. Experimental demonstration of 3D polarimetric imaging of a 3D object attached to two orthogonal linear polarizers is presented. To the best of our knowledge, this is the first report on 3D polarimetric sensing imaging and 3D optical reconstruction by integral imaging.     

Application d'un modéle de l'état liquide à une monocouche de xénon ou de krypton adsorbées sur la surface (0001) du graphite

A phenomenological model of three-dimensional (3D) liquids is applied to a xenon or krypton monolayer adsorbed on (0001) graphite. The rare-gas atoms are assumed to be mobile with a short-range order as in 3D liquids. From the study of the equilibrium 3D gas ? 2D solid and 3D gas ? 2D liquid, one can find with reasonable agreement the pressures and temperatures of the 2D triple point determined experimentally by other authors.     

Diffraction management and sub-diffractive solitons in periodically driven Bose-Einstein condensates

We theoretically investigate the diffraction management in Bose-Einstein condensates (BECs) in one- (1D), two- (2D) and three-dimensional (3D) geometries. The management technique is based on the superposition of harmonic lattices’ potentials moving at a common speed but in different directions, leading to a harmonic spatio-temporal modulation of the potential. In this way a reduction in, and eventually the disappearance of usual diffraction and emergence of fourth-order diffraction are achieved. We show sub-diffractive solitons in such a diffraction managed system and demonstrate their stability in 1D, 2D and 3D. In 2D and 3D cases we investigate diffraction management by lattices of different symmetry, and study their influence on the isotropy of solitons.     

Holographic correspondence in topological superconductors

We analytically derive a compatible family of effective field theories that uniquely describe topological superconductors in 3D, their 2D boundary and their 1D defect lines. We start by deriving the topological field theory of a 3D topological superconductor in class DIII, which is consistent with its symmetries. Then we identify the effective theory of a 2D topological superconductor in class D living on the gapped boundary of the 3D system. By employing the holographic correspondence we derive the effective chiral conformal field theory that describes the gapless modes living on the defect lines or effective boundary of the class D topological superconductor. We demonstrate that the chiral central charge is given in terms of the 3D winding number of the bulk which by its turn is equal to the Chern number of its gapped boundary.     

Atom Localization Using a Rydberg State

A theoretical study is presented for two-dimensional (2D) and three-dimensional (3D) atom localization in a four-level atomic system involving a Rydberg state. The scheme is based on a mixture of two well-known V- and ladder-type systems illuminated by a weak probe field as well as control and switching laser beams of larger intensity, which could be standing waves. As a result of space-dependent atom? light interaction and due to the effect of Rydberg electromagnetically induced transparency or Rydberg electromagnetically induced absorption, various 2D and 3D localization structures appear. Specifically, the detecting probability and precision of 2D and 3D atom localization can be remarkably enhanced through suitable adjusting the controlling parameters of the system. The proposed scheme may provide a promising approach to achieve high precision and perfect resolution 2D and 3D atom localization.     

Observation of coexistence of 1D and 2D nanostructures in cobalt dipyrromethene trimer complexes adsorbed on a graphite surface

We report the direct observation of 1D and 2D nanostructures of cobalt dipyrromethene trimer complexes adsorbed on a highly oriented pyrolytic graphite surface using scanning tunneling microscopy (STM). STM images showed two types of ordered structures coexisting on the surface: long 1D molecular chains isolated on the terraces, and 2D hexagonal patterns confined by a 1D chain and/or a graphite step edge. These 1D and 2D structures are attributed to ‘edge-on’ and ‘face-on’ complex alignments on the surface, respectively. In both configurations, substrate-mediated molecule-molecule interactions may play a significant role in stabilizing the nanostructures.     

Extensive scaling from computational homology and Karhunen-Loève decomposition analysis of Rayleigh-Bénard convection experiments

Spatiotemporally chaotic dynamics in laboratory experiments on convection are characterized using a new dimension, D(CH), determined from computational homology. Over a large range of system sizes, D(CH) scales in the same manner as D(KLD), a dimension determined from experimental data using Karhuenen-Loéve decomposition. Moreover, finite-size effects (the presence of boundaries in the experiment) lead to deviations from scaling that are similar for both D(CH) and D(KLD). In the absence of symmetry, D(CH) can be determined more rapidly than D(KLD).     

Effect of Cellular Instability on the Initiation of Cylindrical Detonations

The direct initiation of detonations in one-dimensional(1 D) and two-dimensional(2 D) cylindrical geometries is investigated through numerical simulations. In comparison of 1 D and 2 D simulations, it is found that cellular instability has a negative effect on the 2 D initiation and makes it more difficult to initiate a sustaining 2 D cylindrical detonation. This effect associates closely with the activation energy. For the lower activation energy,the 2 D initiation of cylindrical detonations can be achieved through a subcritical initiation way. With increasing the activation energy; the 2 D cylindrical detonation has increased difficulty in its initiation due to the presence of unreacted pockets behind the detonation front and usually requires rather larger source energy.     

Holovideo: Real-time 3D range video encoding and decoding on GPU

We present a 3D video-encoding technique called Holovideo that is capable of encoding high-resolution 3D videos into standard 2D videos, and then decoding the 2D videos back into 3D rapidly without significant loss of quality. Due to the nature of the algorithm, 2D video compression such as JPEG encoding with QuickTime Run Length Encoding (QTRLE) can be applied with little quality loss, resulting in an effective way to store 3D video at very small file sizes. We found that under a compression ratio of 134:1, Holovideo to OBJ file format, the 3D geometry quality drops at a negligible level. Several sets of 3D videos were captured using a structured light scanner, compressed using the Holovideo codec, and then uncompressed and displayed to demonstrate the effectiveness of the codec. With the use of OpenGL Shaders (GLSL), the 3D video codec can encode and decode in realtime. We demonstrated that for a video size of 512×512, the decoding speed is 28 frames per second (FPS) with a laptop computer using an embedded NVIDIA GeForce 9400 m graphics processing unit (GPU). Encoding can be done with this same setup at 18 FPS, making this technology suitable for applications such as interactive 3D video games and 3D video conferencing.     

Comparison of 87Rb N-resonances for D1 and D2 transitions

We report an experimental comparison of three-photon-absorption resonances (N-resonances) for the D1 and D2 optical transitions of thermal (87)Rb vapor. We find that the D2 N-resonance has better contrast, a broader linewidth, and a more symmetric line shape than the D1 N-resonance. Taken together, these factors imply superior performance for frequency standards operating on alkali D2 N-resonances, in contrast with coherent population trapping resonances, for which the D2 transition provides poorer frequency standard performance than the D1 transition.