4,487 research outputs found

    Photon-meson transition form factors of light pseudoscalar mesons

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    The photon-meson transition form factors of light pseudoscalar mesons π0\pi ^{0}, η\eta, and η′\eta ^{\prime} are systematically calculated in a light-cone framework, which is applicable as a light-cone quark model at low Q2Q^{2} and is also physically in accordance with the light-cone pQCD approach at large Q2Q^{2}. The calculated results agree with the available experimental data at high energy scale. We also predict the low Q2Q^{2} behaviors of the photon-meson transition form factors of π0\pi ^{0}, η\eta and η′\eta ^{\prime }, which are measurable in e+A(Nucleus)→e+A+Me+A({Nucleus})\to e+A+M process via Primakoff effect at JLab and DESY.Comment: 22 Latex pages, 7 figures, Version to appear in PR

    Bond relaxation, electronic and magnetic behavior of 2D metals structures Y on Li(110) surface

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    We investigated the bond, electronic and magnetic behavior of adsorption Yttrium atoms on Lithium (110) surface using a combination of Bond-order-length-strength(BOLS) correlation and density-functional theory(DFT). We found that adsorption Y atoms on Li(110) surfaces form two-dimensional (2D) geometric structures of hexagon, nonagon, solid hexagonal, quadrangle and triangle. The consistent with the magnetic moment are 6.66{\mu}B, 5.54{\mu}B, 0.28{\mu}B, 1.04{\mu}B, 2.81{\mu}B, respectively. In addition, this work could pave the way for design new 2D metals electronic and magnetic properties

    Ground state fidelity in bond-alternative Ising chains with Dzyaloshinskii-Moriya interactions

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    A systematic analysis is performed for quantum phase transitions in a bond-alternative one-dimensional Ising model with a Dzyaloshinskii-Moriya (DM) interaction by using the fidelity of ground state wave functions based on the infinite matrix product states algorithm. For an antiferromagnetic phase, the fidelity per lattice site exhibits a bifurcation, which shows spontaneous symmetry breaking in the system. A critical DM interaction is inversely proportional to an alternating exchange coupling strength for a quantum phase transition. Further, a finite-entanglement scaling of von Neumann entropy with respect to truncation dimensions gives a central charge c = 0.5 at the critical point.Comment: 6 pages, 4 figure

    The Friedmann equation in modified entropy-area relation from entropy force

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    According to the formal holographic principle, a modification to the assumption of holographic principle in Verlinder's investigation of entropy force is obtained. A more precise relation between entropy and area in the holographic system is proposed. With the entropy corrections to the area-relation, we derivate Newton's laws and Einstein equation with a static spherically symmetric holographic screen. Furthermore we derived the correction terms to the modified Friedmann equation of the FRW universe starting from the holographic principle and the Debye model.Comment: Mod. Phys. Lett. A26, 489-500 (2011

    Virtual medical plant modeling based on L-system

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    Background: Searching the drug molecules from the medicinal plants become more and more popular given that herbalcomponents have been widely considered to be safe. In medical virtual plant studies, development rules are difficult to be extracted, the construction of plant organs is highly dependent on equipment and the process is complicated.Aim: To establish three-dimensional structural virtual plant growth model.Methods: The quasi-binary tree structure and its properties were obtained through the research of theory on binary tree, then the relationship between quasi-binary tree structure and plant three-dimensional branching structure model was analyzed, and the three-dimensional morphology of plants was described.Results: A three-dimensional plant branch structure pattern extracting algorithm based on quasi-binary tree structure. By using 3-D L-system method, the extracted rules were systematized, and standardized. Further more, we built a comprehensive L-model system. With the aid of graphics and PlantVR, we implemented the plant shape and 3-D structure’s reconstruction.Conclusion: Three-dimensional structure virtual plant growth model based on time- controlled L-system has been successfully established.Keywords: Drug R&D, toxicity, medical plants, fractals; L-system; quasi binary-trees
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