4,208 research outputs found
Feshbach resonance scattering under cylindrical harmonic confinement
A problem of collisions of atoms with two-channel zero-range interaction in
an atomic waveguide is solved by using of a renormalization procedure. A
matching of the solution to a solution of the related one-dimensional problem
leads to relation between the one-dimensional and three-dimensional scattering
parameters. The scattering amplitude and bound states for the confined system
demonstrate differences from the related free and one-dimensional systems.Comment: Completely rewritten version,8 pages with 5 figures, uses REVTe
On quantization of nondispersive wave packets
Canonical commutation relations for the Bateman-Hillion type nondispersive
wave packets are constructedComment: LaTeX, 10 page
Any l-state analytical solutions of the Klein-Gordon equation for the Woods-Saxon potential
The radial part of the Klein-Gordon equation for the Woods-Saxon potential is
solved. In our calculations, we have applied the Nikiforov-Uvarov method by
using the Pekeris approximation to the centrifugal potential for any
states. The exact bound state energy eigenvalues and the corresponding
eigenfunctions are obtained on the various values of the quantum numbers
and . The non-relativistic limit of the bound state energy spectrum was also
found.Comment: 15 pages, 1 tabl
The nature and function of the categories in the philosophy of Immanuel Kant, James Ward, S. Alexander
The aim of this investigation is to discuss the merits of the three radically divergent views as to the nature and function of the categories held by Kant, Ward and Alexander.The scope of the study is expressly limited to considerations and problems of a general nature with reference to the epistemo-logical categories. Consequently, if, as some maintain, there are categories unique to the several sciences, our discussion may be described as confined to the categories of Consciousness. It is, therefore, not directly concerned with such subsidiary problems as the number of the categories, or the status of unique categories in such special sciences as morality and aesthetics.These delimitations of the problem require no apology. They are justified on the methodological principle that the basic issues of a problem should be thoroughly investigated and clearly defined before embarking on subsidiary questions.This subject was suggested some years ago by the very cavalier treatment of a priori categories in most contemporary thought. The recent appearance of several works giving explicit attention to the nature of the categories is a gratifying assurance that the problem is not a dead issue.The somewhat lengthy discussion of Kant is due (i) to the sharing of Professor Alexander's conviction "that with or after Plato there is nothing comparable in importance upon this subject with what may be learned from him,"; (ii) Exposition of Kant must be supported by detailed and extensive evidence in view of the conflicts of doctrine in the master himself, and the divergencies of interpretation among his expositors.In tracing the growth and development of the Kantian theory of categories in the seventies, the dating of the Reflexionen by Adickes in the Berlin edition is assumed as authoritative
Non-perturbative solutions in the electro-weak theory with condensate and the -quark mass
We apply Bogoliubov compensation principle to the gauge electro-weak
interaction to demonstrate a spontaneous generation of anomalous three-boson
gauge invariant effective interaction. The non-trivial solution of compensation
equations uniquely defines the form-factor of the anomalous interaction and
parameters of the theory including value of gauge electro-weak coupling
in satisfactory agreement with its experimental value. A possibility
of spontaneous generation of effective four-fermion interaction of heavy quarks
is also demonstrated. This interaction defines an equation for a scalar bound
state of heavy quarks which serve as a substitute for the elementary scalar
Higgs doublet. As a result we calculate the -quark mass
in satisfactory agreement with the experimental value. The results strongly
support idea of condensate as a source of the electro-weak symmetry
breaking.Comment: 16 pages, 5 figures. arXiv admin note: substantial overlap with
arXiv:1103.395
CDF Wjj anomaly as a non-perturbative effect of the electro-weak interaction
The recently reported CDF excess at in invariant mass
distribution of jet pairs accompanying -boson is tentatively interpreted as
a bound state of two decaying to quark-anti-quark pair. Non-perturbative
effects of EW interaction obtained by application of Bogoliubov compensation
approach lead to such bound state due to existence of anomalous three-boson
gauge-invariant effective interaction. The application of this scheme gives
satisfactory agreement with existing data without any adjusting parameter but
the bound state mass .Comment: 5 pages, 2 figure
Pair creation by a photon in a strong magnetic field
The process of pair creation by a photon in a strong magnetic field is
investigated basing on the polarization operator in the field. The total
probability of the process is found in a relatively simple form. The
probability exhibits a "saw-tooth" pattern because of divergences arising when
the electron and positron are created at threshold of the Landau energy levels.
The pattern will be washed out at averaging over any smooth photon energy
distribution. The new results are obtained in the scope of the quasiclassical
approach: 1) in the case when the magnetic field is the
critical field) the new formulation extends the photon energy interval to the
case when the created particles are not ultrarelativistic; 2) the correction to
the standard quasiclassical approximation is found showing the range of
applicability of the approach at high photon energy as well. The very important
conclusion is that for both cases and the results of
the quasiclassical calculation are very close to averaged probabilities of
exact theory in a very wide range of photon energies. The quasiclassical
approximation is valid also for the energy distribution if the electron and
positron are created on enough high levels.Comment: 21 pages, 6 figure
HIV infection and domestic smoke exposure, but not human papillomavirus, are risk factors for esophageal squamous cell carcinoma in Zambia: a case-control study
(c) 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
Dynamic properties of the spin-1/2 XY chain with three-site interactions
We consider a spin-1/2 XY chain in a transverse (z) field with multi-site
interactions. The additional terms introduced into the Hamiltonian involve
products of spin components related to three adjacent sites. A Jordan-Wigner
transformation leads to a simple bilinear Fermi form for the resulting
Hamiltonian and hence the spin model admits a rigorous analysis. We point out
the close relationships between several variants of the model which were
discussed separately in previous studies. The ground-state phases (ferromagnet
and two kinds of spin liquid) of the model are reflected in the dynamic
structure factors of the spin chains, which are the main focus in this study.
First we consider the zz dynamic structure factor reporting for this quantity a
closed-form expression and analyzing the properties of the two-fermion
(particle-hole) excitation continuum which governs the dynamics of transverse
spin component fluctuations and of some other local operator fluctuations. Then
we examine the xx dynamic structure factor which is governed by many-fermion
excitations, reporting both analytical and numerical results. We discuss some
easily recognized features of the dynamic structure factors which are
signatures for the presence of the three-site interactions.Comment: 28 pages, 10 fugure
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