15,406 research outputs found
Family of Hermitian Low-Momentum Nucleon Interactions with Phase Shift Equivalence
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
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
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
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
We describe a lattice calculation of the matrix elements relevant for
glueball production in 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
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
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
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)
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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