15,406 research outputs found

    Family of Hermitian Low-Momentum Nucleon Interactions with Phase Shift Equivalence

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    Using a Schmidt orthogonalization transformation, a family of Hermitian low-momentum NN interactions is derived from the non-Hermitian Lee-Suzuki (LS) low-momentum NN interaction. As special cases, our transformation reproduces the Hermitian interactions for Okubo and Andreozzi. Aside from their common preservation of the deuteron binding energy, these Hermitian interactions are shown to be phase shift equivalent, all preserving the empirical phase shifts up to decimation scale Lambda. Employing a solvable matrix model, the Hermitian interactions given by different orthogonalization transformations are studied; the interactions can be very different from each other particularly when there is a strong intruder state influence. However, because the parent LS low-momentum NN interaction is only slightly non-Hermitian, the Hermitian low-momentum nucleon interactions given by our transformations, including the Okubo and Andreozzi ones, are all rather similar to each other. Shell model matrix elements given by the LS and several Hermitian low-momentum interactions are compared.Comment: 10 pages, 7 figure

    Density Fluctuations in the Oscillatory Phase of Nonclassical Inflaton in FRW Universe

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    Using coherent and squeezed state formalisms of quantum optics for a minimally coupled non-classical inflaton in the FRW mertic is studied, in semiclassical theory of gravity. The leading order solution for the semiclassical Einstein equations in the coherent, squeezed and squeezed vacuum states are obtained perturbatively and are exhibit powerlaw expansion behaviour. The validity of the semiclassical theory is examined in the squeezed vacuum state in the oscillatory phase of the inflaton. The semiclassical theory in the oscillatory phase of the non-classical inflaton holds only if the associated squeezing parameter is much less compared to unity. Quantum fluctuations of the inflaton is also examined in coherent and squeezed state formalisms.Comment: 14 pages, 2 figures, To appear in Int.J.Mod.Phys.

    Low momentum nucleon-nucleon potential and shell model effective interactions

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    A low momentum nucleon-nucleon (NN) potential V-low-k is derived from meson exhange potentials by integrating out the model dependent high momentum modes of V_NN. The smooth and approximately unique V-low-k is used as input for shell model calculations instead of the usual Brueckner G matrix. Such an approach eliminates the nuclear mass dependence of the input interaction one finds in the G matrix approach, allowing the same input interaction to be used in different nuclear regions. Shell model calculations of 18O, 134Te and 135I using the same input V-low-k have been performed. For cut-off momentum Lambda in the vicinity of 2 fm-1, our calculated low-lying spectra for these nuclei are in good agreement with experiments, and are weakly dependent on Lambda.Comment: 5 pages, 5 figure

    HR practice, organisational commitment & citizenship behaviour in Taiwan

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    Purpose (mandatory) The study examines the relationships between HR practice (four aspects), organisational commitment and citizenship behaviour at primary schools in Taiwan. The four HR aspects include: (1) recruitment and placement (RP), (2) teaching, education and career development (TEC), (3) support, communication and retention (SCR), and (4) performance and appraisal (PA). Design/methodology/approach (mandatory) With the assistance from the school HR managers and using an anti-common method variance strategy, research data from 568 incumbent teachers in Taiwan are collected, analysed and evaluated. Findings (mandatory) Different from prior studies, highlighting the merits of HR practice, the study discovers that HR practice may not necessarily contribute to citizenship behaviour. Teachers with positive perceptions of RP and TEC are more likely to demonstrate citizenship behaviour, whereas teachers with positive perceptions of SCR and PA are not. In addition, the study finds three moderators: affective organisational commitment (AOC), rank of positions, and campus size. The analysis shows that teachers with more AOC, higher positions and from smaller campus are more likely to demonstrate OCB. Originality/value (mandatory) The study provides a closer look at the HR-OCB relationship in Taiwan. It reveals that a positive perception of HR practice may not necessarily contribute to OCB occurrence. In addition, the results indicate that teachers have different views about varying HR aspects. Specifically, aspects of recruitment and placement and teaching, education and career development receive relatively higher levels of positive perception, whereas aspects of SCR and PA receive relatively lower levels of positive perception. Questions arise as to whether HR practice may lead to more OCB at primary schools. If this statement is true, school managers shall think further of how to promote OCB using other policies, rather than relying on the HR practice investigated here

    Glueball matrix elements on anisotropic lattices

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    We describe a lattice calculation of the matrix elements relevant for glueball production in J/ψJ / \psi radiative decays. The techniques for such a calculation on anisotropic lattices with an improved action are outlined. We present preliminary results showing the efficacy of the computational method.Comment: 3 pages (LaTeX), 3 figures (PostScript), Presented at Lattice '9

    Supernova neutrinos in the light of FCNC

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    We study the effect of including flavor changing neutral currents (FCNC) in the analysis of the neutrino signal of a supernova burst. When we include the effect of the FCNC which are beyond the standard model (SM) in the study of the MSW resonant conversion, we obtain dramatic changes in the \Delta m^2-sin^2(2\theta) probability contours for neutrino detection.Comment: 8 pages in ReVTeX,3 figures. Revised manuscript submitted to Phys. Rev.

    Realistic shell-model calculations for proton particle-neutron hole nuclei around 132Sn

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    We have performed shell-model calculations for nuclei with proton particles and neutron holes around 132Sn using a realistic effective interaction derived from the CD-Bonn nucleon-nucleon potential. For the proton-neutron channel this is explicitly done in the particle-hole formalism. The calculated results are compared with the available experimental data, particular attention being focused on the proton particle-neutron hole multiplets. A very good agreement is obtained for all the four nuclei considered, 132Sb, 130Sb, 133Te and 131Sb. We predict many low-energy states which have no experimental counterpart. This may stimulate, and be helpful to, future experiments.Comment: 8 pages, 6 figures, to be published on Physical Review

    Heat Conduction Process on Community Networks as a Recommendation Model

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    Using heat conduction mechanism on a social network we develop a systematic method to predict missing values as recommendations. This method can treat very large matrices that are typical of internet communities. In particular, with an innovative, exact formulation that accommodates arbitrary boundary condition, our method is easy to use in real applications. The performance is assessed by comparing with traditional recommendation methods using real data.Comment: 4 pages, 2 figure

    Combustion of LOX with H2(sub g) under subcritical, critical, and supercritical conditions (Task 1) and experimental observation of dense spray and mixing of impinging jets (Task 2)

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    The objective was to achieve a better understanding of the combustion processes of liquid oxygen and gaseous hydrogen under broad range of pressure covering subcritical, critical, and supercritical conditions. The scope of the experimental work falls into the following areas: (1) design of the overall experimental setup; (2) modification of an existing windowed high pressure chamber; (3) design of the LOX feeding system; (4) provision of the safety features in the test rig design; (5) LOX cleanliness requirements; (6) cold shock testing; (7) implementation of data acquisition systems; (8) preliminary tests for system checkout; (9) modification of LOX feeding system; and (10) evaporation tests. Progress in each area is discussed
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