2,762 research outputs found
Computations of Three-Body Continuum Spectra
We formulate a method to solve the coordinate space Faddeev equations for
positive energies. The method employs hyperspherical coordinates and analytical
expressions for the effective potentials at large distances. Realistic
computations of the parameters of the resonances and the strength functions are
carried out for the Borromean halo nucleus 6He (n+n+alpha) for J = 0+, 0-, 1+,
1-, 2+,2-. PACS numbers: 21.45.+v, 11.80.Jy, 31.15.Ja, 21.60.GxComment: 10 pages, 3 postscript figures, LaTeX, epsf.sty, corrected misprints
in the caption of Fig.
Three-Body Halos in Two Dimensions
A method to study weakly bound three-body quantum systems in two dimensions
is formulated in coordinate space for short-range potentials. Occurrences of
spatially extended structures (halos) are investigated. Borromean systems are
shown to exist in two dimensions for a certain class of potentials. An
extensive numerical investigation shows that a weakly bound two-body state
gives rise to two weakly bound three-body states, a reminiscence of the Efimov
effect in three dimensions. The properties of these two states in the weak
binding limit turn out to be universal.
PACS number(s): 03.65.Ge, 21.45.+v, 31.15.Ja, 02.60NmComment: 9 pages, 2 postscript figures, LaTeX, epsf.st
Automated control of temperature regimes of alloyed steel products based on multiprocessors computing systems
Development features and use of multiprocessor computing system with its mathematical support and software for heat treatment modes simulation of metal billets are considered. The application of modern multiprocessor computing technologies is proposed for increasing the speed and efficiency of computation, which enables to effectively control technological processes. Through the special software the multiprocessor system is able to set and control necessary temperature conditions on all plane of cross-sectional of standard at heating and self-control of metal, and if necessary maybe began to control the thermal mode of treatment in the interval of temperatures of annealing
Reading-out the state of a flux qubit by Josephson transmission line solitons
We describe the read-out process of the state of a Josephson flux qubit via
solitons in Josephson transmission lines (JTL) as they are in use in the
standard rapid single flux quantum (RSFQ) technology. We consider the situation
where the information about the state of the qubit is stored in the time delay
of the soliton. We analyze dissipative underdamped JTLs, take into account
their jitter, and provide estimates of the measuring time and efficiency of the
measurement for relevant experimental parameters.Comment: 13 pages, 12 figure
Collective Decoherence of Nuclear Spin Clusters
The problem of dipole-dipole decoherence of nuclear spins is considered for
strongly entangled spin cluster. Our results show that its dynamics can be
described as the decoherence due to interaction with a composite bath
consisting of fully correlated and uncorrelated parts. The correlated term
causes the slower decay of coherence at larger times. The decoherence rate
scales up as a square root of the number of spins giving the linear scaling of
the resulting error. Our theory is consistent with recent experiment reported
in decoherence of correlated spin clusters.Comment: 4 pages, 4 figure
Coherent Schwinger Interaction from Darboux Transformation
The exactly solvable scalar-tensor potential of the four-component Dirac
equation has been obtained by the Darboux transformation method. The
constructed potential has been interpreted in terms of nucleon-nucleon and
Schwinger interactions of neutral particles with lattice sites during their
channeling Hamiltonians of a Schwinger type is obtained by means of the Darboux
transformation chain. The analitic structure of the Lyapunov function of
periodic continuation for each of the Hamiltonians of the family is considered.Comment: 12 pages, Latex, six figures; six sections, one figure adde
Metallurgical thermophysics processes identification based on extreme algorithms of high order of accuracy
The article is devoted the problem to researh the materials thermophysical properties by the inverse methods. Corresponding class of mathematical models is derived. The main research purpose is that the simulation models processing procedure as those that are controlled by input parameters, reduce, on the residual principle basis, to an extreme formulation. This approach allows to develop effective algorithms for solving quotient problems on simulation models of arbitrary accuracy order with adaptation of time modes of a thermophysical experiment. A package of applied problems had been developed for solving the coefficient problems of the heat-conductiving with the methods of mathematical simulation. Creation of package had been carried out considering the requirements of the object-oriented programming
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