885 research outputs found
Atom-Atom Scattering Under Cylindrical Harmonic Confinement: Numerical and Analytical Studies of the Confinement Induced Resonance
In a recent article [M. Olshanii, Phys. Rev. Lett. {\bf 81}, 938 (1998)], an
analytic solution of atom-atom scattering with a delta-function pseudopotential
interaction in the presence of transverse harmonic confinement yielded an
effective coupling constant that diverged at a `confinement induced resonance.'
In the present work, we report numerical results that corroborate this
resonance for more realistic model potentials. In addition, we extend the
previous theoretical discussion to include two-atom bound states in the
presence of transverse confinement, for which we also report numerical results
hereComment: New version with major revisions. We now provide a detailed physical
interpretation of the confinement-induced resonance in tight atomic
waveguide
Detecting Neutrino Magnetic Moments with Conducting Loops
It is well established that neutrinos have mass, yet it is very difficult to
measure those masses directly. Within the standard model of particle physics,
neutrinos will have an intrinsic magnetic moment proportional to their mass. We
examine the possibility of detecting the magnetic moment using a conducting
loop. According to Faraday's Law of Induction, a magnetic dipole passing
through a conducting loop induces an electromotive force, or EMF, in the loop.
We compute this EMF for neutrinos in several cases, based on a fully covariant
formulation of the problem. We discuss prospects for a real experiment, as well
as the possibility to test the relativistic formulation of intrinsic magnetic
moments.Comment: 6 pages, 4 b/w figures, uses RevTe
Weak measurement takes a simple form for cumulants
A weak measurement on a system is made by coupling a pointer weakly to the
system and then measuring the position of the pointer. If the initial
wavefunction for the pointer is real, the mean displacement of the pointer is
proportional to the so-called weak value of the observable being measured. This
gives an intuitively direct way of understanding weak measurement. However, if
the initial pointer wavefunction takes complex values, the relationship between
pointer displacement and weak value is not quite so simple, as pointed out
recently by R. Jozsa. This is even more striking in the case of sequential weak
measurements. These are carried out by coupling several pointers at different
stages of evolution of the system, and the relationship between the products of
the measured pointer positions and the sequential weak values can become
extremely complicated for an arbitrary initial pointer wavefunction.
Surprisingly, all this complication vanishes when one calculates the cumulants
of pointer positions. These are directly proportional to the cumulants of
sequential weak values. This suggests that cumulants have a fundamental
physical significance for weak measurement
Some remarks on the visible points of a lattice
We comment on the set of visible points of a lattice and its Fourier
transform, thus continuing and generalizing previous work by Schroeder and
Mosseri. A closed formula in terms of Dirichlet series is obtained for the
Bragg part of the Fourier transform. We compare this calculation with the
outcome of an optical Fourier transform of the visible points of the 2D square
lattice.Comment: 9 pages, 3 eps-figures, 1 jpeg-figure; updated version; another
article (by M. Baake, R. V. Moody and P. A. B. Pleasants) with the complete
solution of the spectral problem will follow soon (see math.MG/9906132
Birational Mappings and Matrix Sub-algebra from the Chiral Potts Model
We study birational transformations of the projective space originating from
lattice statistical mechanics, specifically from various chiral Potts models.
Associating these models to \emph{stable patterns} and \emph{signed-patterns},
we give general results which allow us to find \emph{all} chiral -state
spin-edge Potts models when the number of states is a prime or the square
of a prime, as well as several -dependent family of models. We also prove
the absence of monocolor stable signed-pattern with more than four states. This
demonstrates a conjecture about cyclic Hadamard matrices in a particular case.
The birational transformations associated to these lattice spin-edge models
show complexity reduction. In particular we recover a one-parameter family of
integrable transformations, for which we give a matrix representationComment: 22 pages 0 figure The paper has been reorganized, splitting the
results into two sections : results pertaining to Physics and results
pertaining to Mathematic
Comparison between two cases study on water kiosks
Bottled water consumption in Europe began in the 70s. Environmental impact derived from water production chain is very significant: for example plastic bottles use, oil consumption for bottle production, air emission from vehicles transporting bottles, not recycled plastic packages, etc. In this research an environmental and economic impact evaluation was presented for two case studies, regarding water kiosk design with the aim of supplying controlled natural and sparkling water with better organoleptic quality compared to water directly supplied from aqueduct
The Lerch Zeta Function II. Analytic Continuation
This is the second of four papers that study algebraic and analytic
structures associated with the Lerch zeta function. In this paper we
analytically continue it as a function of three complex variables. We that it
is well defined as a multivalued function on the manifold M equal to C^3 with
the hyperplanes corresponding to integer values of the two variables a and c
removed. We show that it becomes single valued on the maximal abelian cover of
M. We compute the monodromy functions describing the multivalued nature of this
function on M, and determine various of their properties.Comment: 29 pages, 3 figures; v2 notation changes, homotopy action on lef
Interpolation function of the genocchi type polynomials
The main purpose of this paper is to construct not only generating functions
of the new approach Genocchi type numbers and polynomials but also
interpolation function of these numbers and polynomials which are related to a,
b, c arbitrary positive real parameters. We prove multiplication theorem of
these polynomials. Furthermore, we give some identities and applications
associated with these numbers, polynomials and their interpolation functions.Comment: 14 page
Spin-dependent electron-impurity scattering in two-dimensional electron systems
We present a theoretical study of elastic spin-dependent electron scattering
caused by a charged impurity in the vicinity of a two-dimensional electron gas.
We find that the symmetry properties of the spin-dependent differential
scattering cross section are different for an impurity located in the plane of
the electron gas and for one at a finite distance from the plane. We show that
in the latter case asymmetric (`skew') scattering can arise if the polarization
of the incident electron has a finite projection on the plane spanned by the
normal vector of the two-dimensional electron gas and the initial propagation
direction. In specially preparated samples this scattering mechanism may give
rise to a Hall-like effect in the presence of an in-plane magnetic field.Comment: 4.1 pages, 2 figure
Critical analysis of strategies for PM reduction in urban areas
This paper presents an overview of practical strategies that can be adopted
for reducing the particulate matter concentration in urban areas. Each
strategy is analyzed taking into account the latest results of the scientific
literature. A discussion useful for pointing out some problems to be solved
for their correct adoptions completes the paper
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