74,713 research outputs found
An architecture for intelligent task interruption
In the design of real time systems the capability for task interruption is often considered essential. The problem of task interruption in knowledge-based domains is examined. It is proposed that task interruption can be often avoided by using appropriate functional architectures and knowledge engineering principles. Situations for which task interruption is indispensable, a preliminary architecture based on priority hierarchies is described
Classification of Multipartite Entanglement via Negativity Fonts
Partial transposition of state operator is a well known tool to detect
quantum correlations between two parts of a composite system. In this letter,
the global partial transpose (GPT) is linked to conceptually multipartite
underlying structures in a state - the negativity fonts. If K-way negativity
fonts with non zero determinants exist, then selective partial transposition of
a pure state, involving K of the N qubits (K leq N) yields an operator with
negative eigevalues, identifying K-body correlations in the state. Expansion of
GPT interms of K-way partially transposed (KPT) operators reveals the nature of
intricate intrinsic correlations in the state. Classification criteria for
multipartite entangled states, based on underlying structure of global partial
transpose of canonical state, are proposed. Number of N-partite entanglement
types for an N qubit system is found to be 2^{N-1}-N+2, while the number of
major entanglement classes is 2^{N-1}-1. Major classes for three and four qubit
states are listed. Subclasses are determined by the number and type of
negativity fonts in canonical state.Comment: 5 pages, No figures, Corrected typo
On weak shock diffraction in real gases
Asymptotic solutions are obtained for the two-dimensional Euler system for
real gases with appropriate boundary conditions which describe the diffraction
of a weak shock at a right-angled wedge; the real gas effects are characterized
by a van der Waals type equation of state. The behavior of the flow
configuration influenced by the real gas effects, that includes the local
structure near a singular point, is studied in detail.Comment: 14 pages, 1 figure. arXiv admin note: substantial text overlap with
arXiv:1405.066
CP violation in tbW couplings at the LHC
We study in a model-independent way anomalous CP-violating tbW effective
couplings that might arise from new physics in the processes pp-> tW^- X and
pp-> tbar W^+X, followed by semileptonic decay of t and tbar. These processes
have a dependence on effective tbW couplings both in the production process as
well as in the decay of the t or tbar. We propose several CP-violating
asymmetries constructed out of variables in the two processes, including t and
tbar polarization, and energy and azimuthal angles of the decay particles. We
find that it is feasible to probe a certain CP-violating combination of
anomalous couplings at the per cent level at the LHC for centre-of-mass energy
14 TeV and an integrated luminosity of 10 fb^{-1}.Comment: 12 pages, 2 Figure
Magnetization in electron- and Mn- doped SrTiO3
Mn-doped SrTiO_3.0, when synthesized free of impurities, is a paramagnetic
insulator with interesting dielectric properties. Since delocalized charge
carriers are known to promote ferromagnetism in a large number of systems via
diverse mechanisms, we have looked for the possibility of any intrinsic,
spontaneous magnetization by simultaneous doping of Mn ions and electrons into
SrTiO_3 via oxygen vacancies, thereby forming SrTi_(1-x)Mn_xO_(3-d), to the
extent of making the doped system metallic. We find an absence of any
enhancement of the magnetization in the metallic sample when compared with a
similarly prepared Mn doped, however, insulating sample. Our results, thus, are
not in agreement with a recent observation of a weak ferromagnetism in metallic
Mn doped SrTiO_3 system.Comment: 10 pages and 4 figure
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