4,100 research outputs found

    Theoretical studies of 63Cu Knight shifts of the normal state of YBa2Cu3O7

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    The 63Cu Knight shifts and g factors for the normal state of YBa2Cu3O7 in tetragonal phase are theoretically studied in a uniform way from the high (fourth-) order perturbation formulas of these parameters for a 3d9 ion under tetragonally elongated octahedra. The calculations are quantitatively correlated with the local structure of the Cu2+(2) site in YBa2Cu3O7. The theoretical results show good agreement with the observed values, and the improvements are achieved by adopting fewer adjustable parameters as compared to the previous works. It is found that the significant anisotropy of the Knight shifts is mainly attributed to the anisotropy of the g factors due to the orbital interactions.Comment: 5 page

    Investigations of the g factors and local structure for orthorhombic Cu^{2+}(1) site in fresh PrBa_{2}Cu_{3}O_{6+x} powders

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    The electron paramagnetic resonance (EPR) g factors g_x, g_y and g_z of the orthorhombic Cu^{2+}(1) site in fresh PrBa_{2}Cu_{3}O_{6+x} powders are theoretically investigated using the perturbation formulas of the g factors for a 3d^9 ion under orthorhombically elongated octahedra. The local orthorhombic distortion around the Cu^{2+}(1) site due to the Jahn-Teller effect is described by the orthorhombic field parameters from the superposition model. The [CuO6]^{10-} complex is found to experience an axial elongation of about 0.04 {\AA} along c axis and the relative bond length variation of about 0.09 {\AA} along a and b axes of the Jahn-Teller nature. The theoretical results of the g factors based on the above local structure are in reasonable agreement with the experimental data.Comment: 6 pages, 1 figur

    Analisis Perkembangan Riset Akuntansi Keperilakuan Studi Pada Jurnal Behavioral Research in Accounting (1998-2003)

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    This research aims to analyze growth direction of research in journal of BRIA period 1998-2003. Growth analysis is done at topic / article content, research method, and research subject used by writer of article of BRIA 1998-2003. Topic /article content is classified using taxonomy of Birnberg and Shield (1989) which have been modified by Meyer and Rigsby (2001). Technics of descriptive analysis were used to analyze data. The results show that the most frequent topics written in BRIA as long as 1998-2003 is  Accounting Information Processing, Auditing, and Managerial Control. Most research method used are experiment (29 articles) and survey/questionaire/interview (21 articles). Type of subject most often used is accountant /auditor and student S-1. As a whole, this result not far differ from result of research of Meyer and Rigsby (2001). Thereby, until 14 year publication of BRIA, there are not growth mean in the case of topic, method, and used research subject.  This results show that we still have opportunities of doing new research in order to development of behavioral accountancy science. &nbsp

    QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems

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    We review the developments of QCD multipole expansion and its applications to hadronic transitions and some radiative decays of heavy quarkonia. Theoretical predictions are compsred with updated experimental results.Comment: 23 pages, 7 figures. Some typos corrected, and 3 references adde

    Search for Bc(ns)B_c(ns) via the Bc(ns)Bc(ms)π+πB_c(ns)\to B_c(ms)\pi^+\pi^- transition at LHCb and Z0Z_0 factory

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    It is interesting to study the characteristics of the whole family of BcB_c which contains two different heavy flavors. LHC and the proposed Z0Z^0 factory provide an opportunity because a large database on the BcB_c family will be achieved. BcB_c and its excited states can be identified via their decay modes. As suggested by experimentalists, Bc(ns)Bc+γB_c^*(ns)\to B_c+\gamma is not easy to be clearly measured, instead, the trajectories of π+\pi^+ and π\pi^- occurring in the decay of Bc(ns)Bc(ms)+π+πB_c(ns)\to B_c(ms)+\pi^+\pi^- (n>mn>m) can be unambiguously identified, thus the measurement seems easier and more reliable, therefore this mode is more favorable at early running stage of LHCb and the proposed Z0Z^0 factory. In this work, we calculate the rate of Bc(ns)Bc(ms)+π+πB_c(ns)\to B_c(ms)+\pi^+\pi^- in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z0Z^0 factory are feasible.Comment: 12 pages, 1 figures and 4 tables, acceptted by SCIENCE CHINA Physics, Mechanics & Astronomy (Science in China Series G

    Prospects for detection of Υ(1D)Υ(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi via Υ(3S)Υ(1D)+X\Upsilon(3S) \to \Upsilon(1D) + X

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    At least one state in the first family of D-wave bbˉb \bar b quarkonium levels has been discovered near the predicted mass of 10.16 GeV/c2c^2. This state is probably the one with J=2. This state and the ones with J=1 and J=3 may contribute a detectable amount to the decay Υ(1D)Υ(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi, depending on the partial widths for these decays for which predictions vary considerably. The prospects for detection of the chain Υ(3S)Υ(1D)+XΥππ+X\Upsilon(3S) \to \Upsilon(1D) + X \to \Upsilon \pi \pi + X are discussed.Comment: 4 pages, LaTeX, 1 figure, to be published in Phys. Rev. D, comment added after Eq. (2

    MRI-SegFlow: a novel unsupervised deep learning pipeline enabling accurate vertebral segmentation of MRI images.

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    Most deep learning based vertebral segmentation methods require laborious manual labelling tasks. We aim to establish an unsupervised deep learning pipeline for vertebral segmentation of MR images. We integrate the sub-optimal segmentation results produced by a rule-based method with a unique voting mechanism to provide supervision in the training process for the deep learning model. Preliminary validation shows a high segmentation accuracy achieved by our method without relying on any manual labelling.The clinical relevance of this study is that it provides an efficient vertebral segmentation method with high accuracy. Potential applications are in automated pathology detection and vertebral 3D reconstructions for biomechanical simulations and 3D printing, facilitating clinical decision making, surgical planning and tissue engineering

    The Color-Octet intrinsic charm in η\eta^\prime and BηXB\to \eta^\prime X decays

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    Color-octet mechanism for the decay B\to \eta^\prime X is proposed to explain the large branching ratio of Br(B\to \eta^\prime X)\sim 1\times 10^{-3} recently announced by CLEO. We argue that the inclusive \eta^\prime production in B decays may dominantly come from the Cabbibo favored b\to (\bar c c)_8s process where \bar c c pair is in a color-octet configuration, and followed by the nonperturbative transition (\bar c c)_8\to \eta^\prime X. The color-octet intrinsic charm component in the higher Fock states of \eta^\prime is crucial and is induced by the strong coupling of \eta^\prime to gluons via QCD axial anomaly.Comment: 9 pages, RevTex, 1 PS figur

    Understanding the newly observed Y(4008) by Belle

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    Very recently a new enhancement around 4.05 GeV was observed by Belle experiment. In this short note, we discuss some possible assignments for this enhancement, i.e. ψ(3S)\psi(3S) and DDˉD^*\bar{D}^* molecular state. In these two assignments, Y(4008) can decay into J/ψπ0π0J/\psi\pi^0\pi^0 with comparable branching ratio with that of Y(4008)J/ψπ+πY(4008)\to J/\psi\pi^+\pi^-. Thus one suggests high energy experimentalists to look for Y(4008) in J/ψπ0π0J/\psi\pi^0\pi^0 channel. Furthermore one proposes further experiments to search missing channel DDˉD\bar{D}, DDˉ+h.c.D\bar{D}^*+h.c. and especially χcJπ+ππ0\chi_{cJ}\pi^+\pi^-\pi^0 and ηcπ+ππ0\eta_c\pi^+\pi^-\pi^0, which will be helpful to distinguish ψ(3S)\psi(3S) and DDˉD^*\bar{D}^* molecular state assignments for this new enhancement.Comment: 4 pages, 5 figures. Typos correcte
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