165 research outputs found
Control of emerging-market target and stock performance: Evidence in Vietnam
Joining the upward trend of Global Foreign direct investment and FDI in emerging economies and emerging Asian economies, FDI to Vietnam, especially M&As have increased significantly in both numbers and value of deals from 1995 to 2015. Compared with the deal triggered by a firm from Vietnam or another developing country, the deal triggered by a developed market acquirer dominates the peers in terms of return for the acquirer’s shareholder. The acquirer’s shareholder gains on their investment spent on the Vietnamese acquirer. Especially, the transfer in control of Vietnamese firms to developed-market acquirers drives the statistically
significant return using the event study with the OLS market model approach
The Hubbard model on a complete graph: Exact Analytical results
We derive the analytical expression of the ground state of the Hubbard model
with unconstrained hopping at half filling and for arbitrary lattice sites.Comment: Email:[email protected]
An improved study of the kappa resonance and the non-exotic wave scatterings up to GeV of LASS data
We point out that the dispersion relation for the left hand cut integral
presented in one of our previous paper (Nucl. Phys. {\bf A}733(2004)235) is
actually free of subtraction constant, even for unequal mass elastic
scatterings. A new fit to the LASS data~\cite{Aston} is performed and firm
evidence for the existence of pole is found. The correct use of
analyticity also put strong constraints on threshold parameters -- which are
found to be in good agreement with those obtained from chiral theories. We also
determined the pole parameters of on the second sheet, and
reconfirm the existence of on the third sheet. We stress that the
LASS data do not require them to have the twin pole structure of a typical
Breit--Wigner resonance.Comment: 14 pages + 4 postscript figures; discussions largely expanded;
references added; version to appear in NPA; title changed in the journa
The Constraints of Unitary on Scattering Dispersion Relations
A new dispersion relation for the partial wave scattering matrix
is set up. Using the dispersion relation we generalize the single channel
unitarity condition, , to the entire complex plane, which is
equivalent to the generalized unitarity condition in quantum mechanics. The
pole positions of the resonance and the resonance are
estimated based on the theoretical relations we obtained. The central value of
the pole position is MeV, MeV, obtained after including the the constraint of the Adler zero
condition.Comment: 10 pages with 4 figures, revised version to appear in Phys. Lett.
Vibrational Properties of Nanoscale Materials: From Nanoparticles to Nanocrystalline Materials
The vibrational density of states (VDOS) of nanoclusters and nanocrystalline
materials are derived from molecular-dynamics simulations using empirical
tight-binding potentials. The results show that the VDOS inside nanoclusters
can be understood as that of the corresponding bulk system compressed by the
capillary pressure. At the surface of the nanoparticles the VDOS exhibits a
strong enhancement at low energies and shows structures similar to that found
near flat crystalline surfaces. For the nanocrystalline materials an increased
VDOS is found at high and low phonon energies, in agreement with experimental
findings. The individual VDOS contributions from the grain centers, grain
boundaries, and internal surfaces show that, in the nanocrystalline materials,
the VDOS enhancements are mainly caused by the grain-boundary contributions and
that surface atoms play only a minor role. Although capillary pressures are
also present inside the grains of nanocrystalline materials, their effect on
the VDOS is different than in the cluster case which is probably due to the
inter-grain coupling of the modes via the grain-boundaries.Comment: 10 pages, 7 figures, accepted for publication in Phys. Rev.
The resonance in s wave scatterings
A new unitarization approach incorporated with chiral symmetry is established
and applied to study the elastic scatterings. We demonstrate that the
resonance exists, if the scattering length parameter in the I=1/2, J=0
channel does not deviate much from its value predicted by chiral perturbation
theory. The mass and width of the resonance is found to be
, , obtained by fitting the
LASS data up to 1430MeV. Better determination to the pole parameters is
possible if the chiral predictions on scattering lengths are taken into
account.Comment: Minor corrections made on discussions and typos. 1 ref. added version
to appear in Nuclear Physics
The [1,2] Pad\'e Amplitudes for Scatterings in Chiral Perturbation Theory
A detailed analysis to the [1,2] Pad\'e approximation to the
scattering 2--loop amplitudes in chiral perturbation theory is made.Comment: Discussions expanded and references are added, version to appear in
Physics Letters
A study of charged kappa in
Based on events collected by BESII, the decay
is studied. In the invariant mass
spectrum recoiling against the charged , the charged
particle is found as a low mass enhancement. If a Breit-Wigner function of
constant width is used to parameterize the kappa, its pole locates at MeV/. Also in this channel,
the decay is observed for the first time.
Its branching ratio is .Comment: 14 pages, 4 figure
Osteoprotegerin: A Novel Secreted Protein Involved in the Regulation of Bone Density
AbstractA novel secreted glycoprotein that regulates bone resorption has been identified. The protein, termed Osteoprotegerin (OPG), is a novel member of the TNF receptor superfamily. In vivo, hepatic expression of OPG in transgenic mice results in a profound yet nonlethal osteopetrosis, coincident with a decrease in later stages of osteoclast differentiation. These same effects are observed upon administration of recombinant OPG into normal mice. In vitro, osteoclast differentiation from precursor cells is blocked in a dose-dependent manner by recombinant OPG. Furthermore, OPG blocks ovariectomy-associated bone loss in rats. These data show that OPG can act as a soluble factor in the regulation of bone mass and imply a utility for OPG in the treatment of osteoporosis associated with increased osteoclast activity
Field-induced single-ion magnetic behaviour in a highly luminescent Er3+ complex
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