14,967 research outputs found
Physics Beyond SM at RHIC with Polarized Protons
The capabilities of RHIC with polarized protons to test the Lorentz structure
of electroweak interactions and also the properties of MSSM Higgs, should it be
discovered, are discussed.Comment: Report to the 14th International Symposium on Spin Physics, October
16-21, 2000, RCNP, Osaka University, Osaka, Japan. To be published in the
Proceedings, 6 page
Strings in five-dimensional anti-de Sitter space with a symmetry
The equation of motion of an extended object in spacetime reduces to an
ordinary differential equation in the presence of symmetry. By properly
defining of the symmetry with notion of cohomogeneity, we discuss the method
for classifying all these extended objects. We carry out the classification for
the strings in the five-dimensional anti-de Sitter space by the effective use
of the local isomorphism between \SO(4,2) and \SU(2,2). We present a
general method for solving the trajectory of the Nambu-Goto string and apply to
a case obtained by the classification, thereby find a new solution which has
properties unique to odd-dimensional anti-de Sitter spaces. The geometry of the
solution is analized and found to be a timelike helicoid-like surface
Spontaneous thermal runaway as an ultimate failure mechanism of materials
The first theoretical estimate of the shear strength of a perfect crystal was
given by Frenkel [Z. Phys. 37, 572 (1926)]. He assumed that as slip occurred,
two rigid atomic rows in the crystal would move over each other along a slip
plane. Based on this simple model, Frenkel derived the ultimate shear strength
to be about one tenth of the shear modulus. Here we present a theoretical study
showing that catastrophic material failure may occur below Frenkel's ultimate
limit as a result of thermal runaway. We demonstrate that the condition for
thermal runaway to occur is controlled by only two dimensionless variables and,
based on the thermal runaway failure mechanism, we calculate the maximum shear
strength of viscoelastic materials. Moreover, during the thermal
runaway process, the magnitude of strain and temperature progressively localize
in space producing a narrow region of highly deformed material, i.e. a shear
band. We then demonstrate the relevance of this new concept for material
failure known to occur at scales ranging from nanometers to kilometers.Comment: 4 pages, 3 figures. Eq. (6) and Fig. 2a corrected; added references;
improved quality of figure
Preparation of macroscopic quantum superposition states of a cavity field via coupling to a superconducting charge qubit
We propose how to generate macroscopic quantum superposition states using a
microwave cavity containing a superconducting charge qubit. Based on the
measurement of charge states, we show that the superpositions of two
macroscopically distinguishable coherent states of a single-mode cavity field
can be generated by a controllable interaction between a cavity field and a
charge qubit. After such superpositions of the cavity field are created, the
interaction can be switched off by the classical magnetic field, and there is
no information transfer between the cavity field and the charge qubit. We also
discuss the generation of the superpositions of two squeezed coherent states.Comment: 6 page
Safety and efficacy of eculizumab in pediatric patients with aHUS, with or without baseline dialysis
Japan’s Model of Mobile Ecosystem Success: The Case of NTT DoCoMo
This research looks at the adoption of Internet and mobile applications in the United States and Japan. It is the intent ofthis meta-exploratory study to examine factors of success with Japan’s mobile industry over the past decade. Takeshi Natsuno defined the ecosystem as a collection of roles in a collaborative balance. It is here that we began to search for the factors that have had an impact on the success of the mobile industry in Japan over the past two decades. It is the intent of this study to identify and discuss those factors to validate the ecosystem research model and to recommend its use for future research. We found the ecosystem model to be very robust as a model to discuss, categorize, and explain the mobile industry in Japan, leading us to a robust and explanatory push-pull investment model. It is intended that this model will be used for future research. We concluded in this research that risk-taking was the predominant factor influencing the success of the mobile ecosystem in Japan. We found in Japan a clear investment earlier in the process, as the first step in most cases, where mobile carriers, such as NTT DoCoMo, would partner with university labs to develop mobile applications, such as i-Mode and e-payment systems, and then mobile consumers would have new applications and functionality to adopt. The model is very powerful and can be considered for adoption in other countries and maybe for other ecosystems
Equilibrium states and their entropy densities in gauge-invariant C*-systems
A gauge-invariant C*-system is obtained as the fixed point subalgebra of the
infinite tensor product of full matrix algebras under the tensor product
unitary action of a compact group. In the paper, thermodynamics is studied on
such systems and the chemical potential theory developed by Araki, Haag,
Kastler and Takesaki is used. As a generalization of quantum spin system, the
equivalence of the KMS condition, the Gibbs condition and the variational
principle is shown for translation-invariant states. The entropy density of
extremal equilibrium states is also investigated in relation to macroscopic
uniformity.Comment: 20 pages, revised in March 200
Polar Antiferromagnets Produced with Orbital-Order
Polar magnetic states are realized in pseudocubic manganite thin films
fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion
remains an active variable. Several types of orbital-orders were found to
develop large optical second harmonic generation, signaling
broken-inversion-symmetry distinct from their bulk forms and films on (100)
substrates. The observed symmetry-lifting and first-principles calculation both
indicate that the modified JT q2 mode drives Mn-site off-centering upon orbital
order, leading to the possible cooperation of "Mn-site polarization" and
magnetism.Comment: 5 pages, 4 figure
Finite-time blowup for a complex Ginzburg-Landau equation
We prove that negative energy solutions of the complex Ginzburg-Landau
equation blow up in finite time,
where \alpha >0 and \pi /2<\theta <\pi /2. For a fixed initial value , we
obtain estimates of the blow-up time as . It turns out that stays bounded (respectively, goes to
infinity) as in the case where the solution of the
limiting nonlinear Schr\"odinger equation blows up in finite time
(respectively, is global).Comment: 22 page
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