3,702 research outputs found
Finite Volume Effect of Nucleons and the Formation of the Quark-Gluon Plasma
We study a thermodynamically consistent implementation of the nucleon volume
in the mean field theory, and find that this volume has large consequences on
the properties of hadronic matter under extreme conditions such as in
astrophysical objects and high energy heavy-ion collisions. It is shown that we
can reproduce the critical temperature MeV predicted by
lattice QCD calculations for the phase transition from hadronic matter to
quark-gluon plasma, by using parameters which are adjusted to fit all empirical
data for normal nuclear matter.Comment: 11 Latex pages, 4 figures upon reques
Robust fault detection for networked systems with communication delay and data missing
n this paper, the robust fault detection problem is investigated for a class of discrete-time networked systems with unknown input and multiple state delays. A novel measurement model is utilized to represent both the random measurement delays and the stochastic data missing phenomenon, which typically result from the limited capacity of the communication networks. The network status is assumed to vary in a Markovian fashion and its transition probability matrix is uncertain but resides in a known convex set of a polytopic type. The main purpose of this paper is to design a robust fault detection filter such that, for all unknown inputs, possible parameter uncertainties and incomplete measurements, the error between the residual signal and the fault signal is made as small as possible. By casting the addressed robust fault detection problem into an auxiliary robust H∞ filtering problem of a certain Markovian jumping system, a sufficient condition for the existence of the desired robust fault detection filter is established in terms of linear matrix inequalities. A numerical example is provided to illustrate the effectiveness and applicability of the proposed technique
Amplitude analysis of e+e−→VP with the CLEO measurements
AbstractWith the measured cross sections for e+e−→vector–pseudoscalar (VP) at s=3.773 GeV and s=3.671 GeV by the CLEO Collaboration, we perform a global amplitude analysis to study the possible interference effects between the continuum process via virtual photon and the ψ(3770) resonance decay. It is found that such interference may significantly affect the measurement of the ψ(3770)→exclusive non-DD¯ decays. By taking the interference into account, we extract the branching fraction for ψ(3770)→ρπ
Solution Of Wheeler-De Witt Equation, Potential Well And Tunnel Effect
This paper uses the relation of the cosmic scale factor and scalar field to
solve Wheeler-DeWitt equation, gives the tunnel effect of the cosmic scale
factor a and quantum potential well of scalar field, and makes it fit with the
physics of cosmic quantum birth. By solving Wheeler-DeWitt equation we achieve
a general probability distribution of the cosmic birth, and give the analysis
of cosmic quantum birth.Comment: 12 page
Statistics of skyrmions in Quantum Hall systems
We analyze statistical interactions of skyrmions in the quantum Hall system
near a critical filling fraction in the framework of the Ginzburg-Landau model.
The phase picked up by the wave-function during an exchange of two skyrmions
close to is , where is the skyrmion's
spin. In the same setting an exchange of two fully polarized vortices gives
rise to the phase . Skyrmions with odd and even numbers of reversed
spins have different quantum statistics. Condensation of skyrmions with an even
number of reversed spins leads to filling fractions with odd denominators,
while condensation of those with an odd number of reversed spins gives rise to
filling fractions with even denominators.Comment: 6 pages in Latex. addendum - skyrmions with odd or even number of
reversed spins have different quantum statistics. They condense to form
respectively even or odd denominator filling fraction state
Generation of solitary waves by transcritical flow over a step
It is well-known that transcritical flow over a localised obstacle generates upstream
and downstream nonlinear wavetrains. The flow has been successfully modeled in the
framework of the forced Korteweg-de Vries equation, where numerical and asymptotic
analytical solutions have shown that the upstream and downstream nonlinear wavetrains
have the structure of unsteady undular bores, connected by a locally steady solution over
the obstacle, which is elevated on the upstream side and depressed on the downstream
side. In this paper we consider the analogous transcritical flow over a step, primarily in
the context of water waves. We use numerical and asymptotic analytical solutions of the
forced Korteweg-de Vries equation, together with numerical solutions of the full Euler
equations, to demonstrate that a positive step generates only an upstream-propagating
undular bore, and a negative step generates only a downstream-propagating undular bore
Generation of internal undular bores by transcritical flow over topography
In both the ocean and the atmosphere, the interaction of a density stratified flow
with topography can generate large-amplitude, horizontally propagating internal
solitary waves. Often these waves appear as a wave-train, or undular bore. In this
article we focus on the situation when the flow is critical, that is, the flow speed
is close to that of a linear long wave mode. In the weakly nonlinear regime, this
is modeled by the forced Korteweg de Vries equation. We will demonstrate how
Whitham’s modulation theory may be applied to obtain an analytical description
of undular bores, for flow over isolated obstacles and for flow over a step
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