324 research outputs found
Evaluasi Special Event Surabaya Fashion Parade 2012 Yang Diselenggarakan Oleh Tunjungan Plaza Surabaya
Penelitian ini dilakukan untuk mengetahui evaluasi special event Surabaya Fashion Parade 2012 yang diselenggarakan oleh Tunjungan Plaza Surabaya. Special event ini sudah diselenggarakan lima kali tetapi belum pernah dilakukan evaluasi. Jumlah peserta yang mengikuti kompetisi dalam special event ini tampak tidak konsisten. Evaluasi dilihat dari efek proses komunikasi yang terjadi antara panitia penyelenggara event dengan peserta kompetisi dalam event tersebut. Penelitian ini dilakukan dengan metode studi kasus dan menggunakan teknik wawancara. Peneliti menemukan bahwa proses komunikasi antara panitia penyelenggara dengan peserta kompetisi dari mulai pra-event, saat pelaksanaan event hingga event berakhir telah berjalan dengan cukup lancar. Namun masih ada beberapa hal detail yang kurang diperhatikan oleh panitia
Dyson-Schwinger Equation Approach to the QCD Deconfinement Transition and J/Psi Dissociation
We consider an extension of the finite-temperature Dyson-Schwinger equation
(DSE) approach to heavy mesons and quarkonia and apply it to calculate the
cross section for the J/Psi breakup reaction J/Psi + pi --> D + D. We study the
effects of chiral symmetry restoration in the light quark sector on this
process and obtain a critical enhancement of the reaction rate at the chiral/
deconfinement transition. Implications for the kinetics of charmonium
production in ultrarelativistic heavy-ion collisions are discussed with
particular emphasis on the recently observed anomalous J/Psi suppression as a
possible signal for quark matter formation.Comment: 10 pages, 6 figures, sprocl.sty, to appear in: "Progress in
Nonequilibrium Green's functions", M. Bonitz (Ed.), World Scientific,
Singapore, 200
A dynamical, confining model and hot quark stars
We explore the consequences of an equation of state (EOS) obtained in a
confining Dyson-Schwinger equation model of QCD for the structure and stability
of nonstrange quark stars at finite-T, and compare the results with those
obtained using a bag-model EOS. Both models support a temperature profile that
varies over the star's volume and the consequences of this are model
independent. However, in our model the analogue of the bag pressure is
(T,mu)-dependent, which is not the case in the bag model. This is a significant
qualitative difference and comparing the results effects a primary goal of
elucidating the sensitivity of quark star properties to the form of the EOS.Comment: 13 pages, 5 figures, epsfig.sty, elsart.sty. Shortened version to
appear in Phys. Lett. B, qualitatively unmodifie
Aspects and consequences of a dressed-quark-gluon vertex
Features of the dressed-quark-gluon vertex and their role in the gap and
Bethe-Salpeter equations are explored. It is argued that quenched lattice data
indicate the existence of net attraction in the colour-octet projection of the
quark-antiquark scattering kernel. This attraction affects the uniformity with
which solutions of truncated equations converge pointwise to solutions of the
complete gap and vertex equations. For current-quark masses less than the scale
set by dynamical chiral symmetry breaking, the dependence of the
dressed-quark-gluon vertex on the current-quark mass is weak. The study employs
a vertex model whose diagrammatic content is explicitly enumerable. That
enables the systematic construction of a vertex-consistent Bethe-Salpeter
kernel and thereby an exploration of the consequences for the strong
interaction spectrum of attraction in the colour-octet channel. With rising
current-quark mass the rainbow-ladder truncation is shown to provide an
increasingly accurate estimate of a bound state's mass. Moreover, the
calculated splitting between vector and pseudoscalar meson masses vanishes as
the current-quark mass increases, which argues for the mass of the pseudoscalar
partner of the \Upsilon(1S) to be above 9.4 GeV. The absence of
colour-antitriplet diquarks from the strong interaction spectrum is contingent
upon the net amount of attraction in the octet projected quark-antiquark
scattering kernel. There is a window within which diquarks appear. The amount
of attraction suggested by lattice results is outside this domain.Comment: 22 pages, 12 figure
Selected nucleon form factors and a composite scalar diquark
A covariant, composite scalar diquark, Fadde'ev amplitude model for the
nucleon is used to calculate pseudoscalar, isoscalar- and isovector-vector,
axial-vector and scalar nucleon form factors. The last yields the nucleon
sigma-term and on-shell sigma-nucleon coupling. The calculated form factors are
soft, and the couplings are generally in good agreement with experiment and
other determinations. Elements in the dressed-quark-axial-vector vertex that
are not constrained by the Ward-Takahashi identity contribute ~20% to the
magnitude of g_A. The calculation of the nucleon sigma-term elucidates the only
unambiguous means of extrapolating meson-nucleon couplings off the meson
mass-shell.Comment: 12 pages, REVTEX, 5 figures, epsfi
Quark-gluon vertex in arbitrary kinematics
We compute the quark-gluon vertex in quenched lattice QCD, in the Landau
gauge using an off-shell mean-field O(a)-improved fermion action. The complete
vertex is computed in two specific kinematical limits, while the Dirac-vector
part is computed for arbitrary kinematics. We find a nontrivial and rich tensor
structure, including a substantial infrared enhancement of the interaction
strength regardless of kinematics.Comment: 6 pages, 8 figures, talk by JIS at QCD Down Under, Adelaide, 10-19
March 200
Electromagnetic properties of ground and excited state pseudoscalar mesons
The axial-vector Ward-Takahashi identity places constraints on particular
properties of every pseudoscalar meson. For example, in the chiral limit all
pseudoscalar mesons, except the Goldstone mode, decouple from the axial-vector
current. Nevertheless, all neutral pseudoscalar mesons couple to two photons.
The strength of the \pi_n^0 \gamma \gamma coupling, where n=0 denotes the
Goldstone mode, is affected by the Abelian anomaly's continuum contribution.
The effect is material for n \neq 0. The \gamma* \pi_n \gamma* transition form
factor, T_{\pi_n}(Q^2), is nonzero for all n, and T_{\pi_n}(Q^2) \approx
(4\pi^2/3) (f_{\pi_n}/Q^2) at large Q^2. For all pseudoscalars but the
Goldstone mode, this leading contribution vanishes in the chiral limit. In this
instance the ultraviolet power-law behaviour is 1/Q^4 for n \neq 0, and we find
numerically T_{\pi_1}(Q^2) \simeq (4\pi^2/3) (-/Q^4). This subleading
power-law behaviour is always present. In general its coefficient is not simply
related to f_{\pi_n}. The properties of n \neq 0 pseudoscalar mesons are
sensitive to the pointwise behaviour of the long-range piece of the interaction
between light-quarks.Comment: 13 pages, 5 figure
The Information Precision of CBD Office Vacancy Rates
Consistent with the rational expectations information model (REIM), the difference among reported area CBD office vacancy rates is proportional to the level of vacancy, inversely proportional to the size of the inventory, and significantly higher when both a national vendor and a local agent make simultaneous reports. Underlying volatility in the market and the cost and difficulty of acquiring information are the principal causes of the information variance. The difficulties and ambiguities in obtaining information are reviewed and the Diamond REIM model is tested using encountered published vacancy rates for central business districts for the period 1985-1989.
The , , and electromagnetic form factors
The rainbow truncation of the quark Dyson-Schwinger equation is combined with
the ladder Bethe-Salpeter equation for the meson amplitudes and the dressed
quark-photon vertex in a self-consistent Poincar\'e-invariant study of the pion
and kaon electromagnetic form factors in impulse approximation. We demonstrate
explicitly that the current is conserved in this approach and that the obtained
results are independent of the momentum partitioning in the Bethe-Salpeter
amplitudes. With model gluon parameters previously fixed by the condensate, the
pion mass and decay constant, and the kaon mass, the charge radii and spacelike
form factors are found to be in good agreement with the experimental data.Comment: 8 pages, 6 figures, Revte
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