title: The Michelson-Morley experiment and the cosmic velocity of the Earth

abstract:
  The Michelson-Morley experiment was designed to detect the relative motion of
the Earth with respect to a preferred reference frame, the ether, by measuring
the fringe shifts in an optical interferometer. These shifts, that should have
been proportional to the square of the Earth's velocity, were found to be much
smaller than expected. As a consequence, that experiment was taken as an
evidence that there is no ether and, as such, played a crucial role for
deciding between Lorentzian Relativity and Einstein's Special Relativity.
However, according to some authors, the observed Earth's velocity was not
negligibly small. To provide an independent check, we have re-analyzed the
fringe shifts observed in each of the six different sessions of the
Michelson-Morley experiment. They are consistent with a non-zero observable
Earth's velocity $v_{\rm obs} = 8.4 \pm 0.5 km/s$. Assuming the existence of a
preferred reference frame and using Lorentz transformations, this $v_{\rm obs}$
corresponds to a real velocity, in the plane of the interferometer, $v_{\rm
earth} = 201 \pm 12 km/s$. This value, which is remarkably consistent with 1932
Miller's cosmic solution, suggests that the magnitude of the fringe shifts is
determined by the typical velocity of the solar system within our galaxy. This
conclusion is consistent with the results of all classical experiments
(Morley-Miller, Illingworth, Joos, Michelson-Pease-Pearson,...) and with the
existing data from present-day experiments.


title:
Improved neighbor list algorithm in molecular simulations using cell
  decomposition and data sorting method

abstract:
  An improved neighbor list algorithm is proposed to reduce unnecessary
interatomic distance calculations in molecular simulations. It combines the
advantages of Verlet table and cell linked list algorithms by using cell
decomposition approach to accelerate the neighbor list construction speed, and
data sorting method to lower the CPU data cache miss rate, as well as partial
updating method to minimize the unnecessary reconstruction of the neighbor
list. Both serial and parallel performance of molecular dynamics simulation are
evaluated using the proposed algorithm and compared with those using
conventional Verlet table and cell linked list algorithms. Results show that
the new algorithm outperforms the conventional algorithms by a factor of 2~3 in
cases of both small and large number of atoms.


title: Tokamak MHD equilibria with reversed magnetic shear and sheared flow

abstract:
  Analytic solutions of the magnetohydrodynamic equilibrium equations for a
cylindrically symmetric magnetically confined plasma with reversed magnetic
shear, s < 0, and sheared flow are constructed by prescribing the safety
factor-, poloidal velocity- and axial velocity- profiles consistently with
experimental ones.


title: Coherent Anti-Stokes Raman Scattering Heterodyne Interferometry

abstract:
  A new interferometric technique is demonstrated for measuring Coherent
Anti-Stokes Raman Scattering (CARS) signals. Two forward-directed CARS signals
are generated, one in each arm of an interferometer. The deterministic nature
of the CARS process allows for these two signals, when spatially and temporally
overlapped, to interfere with one another. Heterodyne detection can therefore
be employed to increase the sensitivity in CARS signal detection. In addition,
nonlinear CARS interferometry will facilitate the use of this spectroscopic
technique for molecular contrast in Optical Coherence Tomography (OCT).


title:
First-Order Averaging Principles for Maps with Applications to Beam
  Dynamics in Particle Accelerators

abstract:
  For slowly evolving, discrete-time-dependent systems of difference equations
(iterated maps), we believe the simplest means of demonstrating the validity of
the averaging method at first order is by way of a lemma that we call Besjes'
inequality. In this paper, we develop the Besjes inequality for identity maps
with perturbations that are (i) at low-order resonance (periodic with short
period) and (ii) far from low-order resonance in the discrete time. We use
these inequalities to prove corresponding first-order averaging principles,
together with a principle of adiabatic invariance on extended timescales; and
we generalize and apply these mathematical results to model problems in
accelerator beam dynamics, and to the Henon map.


title: A Frictional Cooling Demonstration Experiment with Protons

abstract:
  Muon cooling is the main technological obstacle in the building of a muon
collider. A muon cooling scheme based on Frictional Cooling holds promise in
overcoming this obstacle. An experiment designed to demonstrate the Frictional
Cooling concept using protons was undertaken. Although the results were
inconclusive in the observation of cooling, the data allowed for the
qualification of detailed simulations which are used to simulate the
performance of a muon collider.


title: Low-Cost Data Acquisition Card for School-Network Cosmic Ray Detectors

abstract:
  The Cosmic Ray Observatory Project (CROP) at University of Nebraska/Lincoln
and the Washington Area Large-scale Time coincidence Array (WALTA) at
University of Washington/Seattle are among several outreach projects siting
cosmic-ray detectors at local high schools in cities around North America, to
study the origins and interactions of high-energy cosmic rays. In a
collaboration between QuarkNet, the outreach program based at Fermilab, CROP,
and WALTA, a low-cost data acquisition electronics card has been developed to
collect and synchronize the data from each detector site. The cost for each
card is under US$500 for parts, functionally replacing much more expensive
electronics crates and modules at each high school site. The card has 4 analog
discriminator inputs for photo-multiplier tube signals, a 4-channel
Time-to-Digital converter for local coincidence and time-over-threshold
measurements at 0.75 ns resolution, programmable trigger logic via a CPLD and
microcontroller, and a built-in low-cost GPS receiver/antenna module (via
external cable) to provide event trigger time stamps at better than 100 ns
accuracy. Temperature sensors and a barometer are also integrated to record
environmental data along with the counter data. The card connects to any PC or
laptop via a standard RS-232 serial port for data output and control. The
microcontroller and CPLD are field programmable and therefore make the card
functionality flexible and easy to upgrade.


title: Superluminal Behaviors of Electromagnetic Near-fields

abstract:
  Superluminal phenomena have been reported in many experiments of
electromagnetic wave propagation, where the superluminal behaviors of
evanescent waves are the most interesting ones with the important physical
significances. Consider that evanescent waves are related to the near-zone
fields of electromagnetic sources, based on the first principles, we study the
group velocities of electromagnetic fields in near-field region, and show that
they can be superluminal, which can provide a heuristic interpretation for the
superluminal properties of evanescent waves.


title: LabView Interface for School-Network DAQ Card

abstract:
  A low-cost DAQ card has been developed for school-network cosmic ray detector
projects, providing digitized data from photomultiplier tubes via a standard
serial interface. To facilitate analysis of these data and to provide students
with a starting point for custom readout systems, a model interface has been
developed using the National Instruments LabVIEW(R) system. This user-friendly
interface allows one to initialize the trigger coincidence conditions for
data-taking runs and to monitor incoming or pre-recorded data sets with
updating singles- and coincidence-rate plots and other user-selectable
histograms.


title: Polarized gamma beams on the base of excited crystal

abstract:
  Possibilities of creating high energy polarized photon beams at the end of
bremsstrahlung spectrum and a method for analysis of degree of the beam
polarization are considered in this paper.


title: A double potential model for neutron halo nuclei

abstract:
  It is shown here that loosely bound halo structure of neutron rich nuclei and
the ground state spin of single neutron halo nuclei are correlated and are
consistently explained if one assumes a double potential shell model for these
nuclei.


title:
Single-mode photonic crystal fiber with an effective area of 600
  square-micron and low bending loss

abstract:
  A single-mode all-silica photonic crystal fiber with an effective area of 600
square-micron and low bending loss is demonstrated. The fiber is characterized
in terms of attenuation, chromatic dispersion and modal properties.


title:
Comment on "Total Negative Refraction in Crystals for Ballistic
  Electrons and Light"

abstract:
  In Phys. Rev. Lett. 91, 157404 (2003) Yong Zhang et al. study light
propagation through an interface between two identical but differently oriented
uniaxial crystals. The authors show that the light refraction at the interface
at some region of incident angles is negative. The observed effect of negative
refraction resembles the analogous effect in left-handed materials (LHM)
although the physics is different. In LHM the negative refraction is caused by
a negative group velocity, whereas in the considered case one deals with the
special properties of wave propagation in uniaxial anisotropic media.


title:
W3 theory: robust computational thermochemistry in the kJ/mol accuracy
  range

abstract:
  We are proposing a new computational thermochemistry protocol denoted W3
theory, as a successor to W1 and W2 theory proposed earlier [Martin and De
Oliveira, J. Chem. Phys. 111, 1843 (1999)]. The new method is both more
accurate overall (error statistics for total atomization energies approximately
cut in half) and more robust (particularly towards systems exhibiting
significant nondynamical correlation) than W2 theory. The cardinal improvement
rests in an approximate account for post-CCSD(T) correlation effects. Iterative
T_3 (connected triple excitations) effects exhibit a basis set convergence
behavior similar to the T_3 contribution overall. They almost universally
decrease molecular binding energies. Their inclusion in isolation yields less
accurate results than CCSD(T) nearly across the board: it is only when T_4
(connected quadruple excitations) effects are included that superior
performance is achieved. $T_4$ effects systematically increase molecular
binding energies. Their basis set convergence is quite rapid, and even
CCSDTQ/cc-pVDZ scaled by an empirical factor of 1.2532 will yield a quite
passable quadruples contribution. The effect of still higher-order excitations
was gauged for a subset of molecules (notably the eight-valence electron
systems): T_5 (connected quintuple excitations) contributions reach 0.3
kcal/mol for the pathologically multireference X ^1\Sigma^+_g state of C_2 but
are quite small for other systems. A variety of avenues for achieving accuracy
beyond that of W3 theory were explored, to no significant avail. W3 thus
appears to represent a good compromise between accuracy and computational cost
for those seeking a robust method for computational thermochemistry in the
kJ/mol accuracy range on small systems.


title:
Transverse modulational instability of partially incoherent soliton
  stripes

abstract:
  Based on the Wigner distribution approach, an analysis of the effect of
partial incoherence on the transverse instability of soliton structures in
nonlinear Kerr media is presented. It is explicitly shown, that for a
Lorentzian incoherence spectrum the partial incoherence gives rise to a damping
which counteracts, and tends to suppress, the transverse instability growth.
However, the general picture is more complicated and it is shown that the
effect of the partial incoherence depends crucially on the form of the
incoherence spectrum. In fact, for spectra with finite rms-width, the partial
incoherence may even increase both the growth rate and the range of unstable,
transverse wave numbers.


title:
Vibrational Spectra of the Azabenzenes Revisited: Anharmonic Force
  Fields

abstract:
  Anharmonic force fields and vibrational spectra of the azabenzene series
(pyridine, pyridazine, pyrimidine, pyrazine, s-triazine, 1,2,3-triazine,
1,2,4-triazine and s-tetrazine) and benzene are obtained using density
functional theory (DFT) with the B97-1 exchange-correlation functional and a
triple-zeta plus double polarization (TZ2P) basis set. Overall, the fundamental
frequencies computed by second-order rovibrational perturbation theory are in
excellent agreement with experiment. The resolution of the presently calculated
anharmonic spectra is such that they represent an extremely useful tool for the
assignment and interpretation of the experimental spectra, especially where
resonances are involved.


title: Two dimensional modulational instability in photorefractive media

abstract:
  We study theoretically and experimentally the modulational instability of
broad optical beams in photorefractive nonlinear media. We demonstrate the
impact of the anisotropy of the nonlinearity on the growth rate of periodic
perturbations. Our findings are confirmed by experimental measurements in a
strontium barium niobate photorefractive crystal.


title: Nonlinear interferometric vibrational imaging

abstract:
  Coherent Anti-Stokes Raman Scattering (CARS) processes are ``coherent,'' but
the phase of the anti-Stokes radiation is usually lost by most incoherent
spectroscopic CARS measurements. We propose a novel Raman microscopy imaging
method called Nonlinear Interferometric Vibrational Imaging, which measures
Raman spectra by obtaining the temporal anti-Stokes signal through nonlinear
interferometry. With a more complete knowledge of the anti-Stokes signal, we
show through simulations that a high-resolution Raman spectrum can be obtained
of a molecule in a single pulse using broadband radiation. This could be useful
for identifying the three-dimensional spatial distribution of molecular species
in tissue.


title: Light Filaments Without Self Guiding

abstract:
  An examination of the propagation of intense 200 fs pulses in water reveals
light filaments not sustained by the balance between Kerr-induced self-focusing
and plasma-induced defocusing. Their appearance is interpreted as the
consequence of a spontaneous reshaping of the wave packet form a gaussian into
a conical wave, driven by the requirement of maximum localization, minimum
losses and stationarity in the presence of non-linear absorption.


title:
Multi - nucleon forces and the equivalence of different multi - cluster
  structures

abstract:
  At present it is believed that different multi-cluster structures for light
nuclei may represent equivalent states of these nuclei. Here it is proven that
once we take account of Three Body and Four Body Forces then this equivalence
is lost.


title: The Maxwell Demon and Market Efficiency

abstract:
  This paper addresses two seemingly unrelated problems, (a) What is the
entropy and energy accounting in the Maxwell Demon problem? and (b) How can the
efficiency of markets be measured? Here we show, in a simple model for the
Maxwell Demon, the entropy of the universe increases by an amount
eta=0.839995520 in going from a random state to an ordered state and by an
amount eta*=2.731382 in going from one sorted state to another sorted state. We
calculate the efficiency of an engine driven by the Maxwell sorting process.
The efficiency depends only on the temperatures of the particles and of the
computer the Demon uses to sort the particles. We also show the approach is
general and create a simple model of a stock market in which the Limit Trader
plays the role of the Maxwell Demon. We use this model to define and measure
market efficiency.


title: Again on the non-existence of gravitational waves and of black holes

abstract:
  Very straightforward arguments proving the physical non-existence of GW's and
of BH's. They are so simple that even the members of the Wheelerian
establishment will understand them.


title:
Reconstruction of the three mechanical material constants of a lossy
  fluid-like cylinder from low-frequency scattered acoustic fields

abstract:
  The inverse medium problem for a circular cylindrical domain is studied using
low-frequency acoustic waves as the probe radiation. It is shown that to second
order in $k_{0}a$ ($k_{0}$ the wavenumber in the host medium, $a$ the radius of
the cylinder), only the first three terms (i.e., of orders 0, -1 and +1) in the
partial wave representation of the scattered field are non-vanishing, and the
material parameters enter into these terms in explicit manner. Moreover, the
zeroth-order term contains only two of the unknown material constants (i.e.,
the real and imaginary parts of complex compressibility of the cylinder
$\kappa_{1}$) whereas the $\pm 1$ order terms contain the other material
constant (i.e., the density of the cylinder $\rho_{1}$). A method, relying on
the knowledge of the totality of the far-zone scattered field and resulting in
explicit expressions for $\rho_{1}$ and $\kappa_{1}$, is devised and shown to
give highly-accurate estimates of these quantities even for frequencies such
that $k_{0}a$ is as large as 0.1.


title:
Trapping and Steering on Lattice Strings: Virtual Slow Waves,
  Directional and Non-propagating Excitations

abstract:
  Using a lattice string model, a number of peculiar excitation situations
related to non-propagating excitations and non-radiating sources are
demonstrated. External fields can be used to trap excitations locally but also
lead to the ability to steer such excitations dynamically as long as the
steering is slower than the field's wave propagation. I present explicit
constructions of a number of examples, including temporally limited
non-propagating excitations, directional excitation and virtually slowed
propagation. Using these dynamical lattice constructions I demonstrate that
neither persistent temporal oscillation nor static localization are necessary
for non-propagating excitations to occur.


title: Nonlinear Phenomena In Ferromagnetic Double Layers

abstract:
  The non-stationary nonlinear models of magnetostatic waves propagation in
layered ferromagnetic structures are developed. This models are based on use of
the coupled nonlinear Schrodinger equations for amplitude of a bending around
taking into account an electrodynamic coupling between layers. The basic
nonlinear processes in such structures, in particular, the effects of
self-modulation and solitons formation are studied numerically, in comparison
with the similar effects in single ferromagnetic films.


title: GPS Time Synchronization in School-Network Cosmic Ray Detectors

abstract:
  The QuarkNet DAQ card for school-network cosmic ray detectors provides a
low-cost alternative to using standard particle and nuclear physics fast pulse
electronics modules. Individual detector stations, each consisting of 4
scintillation counter modules, front-end electronics, and a GPS receiver,
produce a stream of data in form of ASCII text strings in identifiable set of
formats for different functions. The card includes a low-cost GPS receiver
module, which permits timestamping event triggers to about 50 nanosecond
accuracy in UTC between widely separated sites. The technique used for
obtaining precise GPS time employs the 1PPS signal, which is not normally
available to users of the commercial GPS module. We had the stock model
slightly custom-modified to access this signal. The method for deriving time
values was adapted from methods developed for the K2K long-baseline neutrino
experiment. Performance of the low-cost GPS module used is compared to that of
a more expensive unit with known quality.


title: Search for Possible Variation of the Fine Structure Constant

abstract:
  Determination of the fine structure constant alpha and search for its
possible variation are considered. We focus on a role of the fine structure
constant in modern physics and discuss precision tests of quantum
electrodynamics. Different methods of a search for possible variations of
fundamental constants are compared and those related to optical measurements
are considered in detail.


title:
Space-time nonlinear compression and three-dimensional complex trapping
  in normal dispersion

abstract:
  In positive phase-mismatched SHG and normal dispersion, a gaussian
spatio-temporal pulse transforms spontaneously into a X-pulse, underlies
spatio-temporal compression and eventually leads to stationary 3-D propagation.
Experimental and numerical data are provided


title: Methods of electron beam bunching

abstract:
  A review of electron beam bunching methods and new bunching methods are
presented. Linear accelerator, storage ring and buncher technologies offer
high-beam quality and short bunches necessary for operation of high efficiency,
high-power, high-degree monochromatic prebunched FELs in optical and X-ray
regions.


title: Fractal rain distributions and chaotic advection

abstract:
  Localized rain events have been found to follow power-law distributions over
several decades, suggesting parallels between precipitation and seismic
activity [O. Peters et al., PRL 88, 018701 (2002)]. Similar power laws can be
generated by treating raindrops as passive tracers advected by the velocity
field of a two-dimensional system of point vortices [R. Dickman, PRL 90, 108701
(2003)]. Here I review observational and theoretical aspects of fractal rain
distributions and chaotic advection, and present new results on tracer
distributions in the vortex model.


title:
On the calculation of diffusion coefficients in confined fluids and
  interfaces with an application to the liquid-vapor interface of water

abstract:
  We propose a general methodology for calculating the self-diffusion tensor
from molecular dynamics for a liquid with a liquid-gas or liquid-solid
interface. The standard method used in bulk fluids, based on computing the mean
square displacement as a function of time and extracting the asymptotic linear
time dependence from this, is not valid for systems with interfaces or for
confined fluids. The method proposed here is based on imposing virtual boundary
conditions on the molecular system and computing survival probabilities and
specified time correlation functions in different layers of the fluid up to and
including the interfacial layer. By running dual simulations, one based on MD
and the other based on Langevin dynamics, using the same boundary conditions,
one can fit the Langevin survival probability at long times to the MD computed
survival probability, thereby determining the diffusion coefficient as a
function of distance of the layers from the interface. We compute the elements
of the diffusion tensor of water as a function of distance from the liquid
vapor interface of water. Far from the interface the diffusion tensor is found
to be isotropic, as expected, and the diffusion coefficient has the value
$D\approx$ .22\AA$^2$/psec in agreement with what is found in the bulk liquid.
In the interfacial region the diffusion tensor is axially anisotropic, with
values of $D_{\parallel}\approx$. 8\AA$^2$/psec and $D_{\perp}\approx$.
5\AA$^2$/psec for the components parallel and normal the interface surface
respectively. We also show that diffusion in confined geometries can be
calculated by imposing appropriate boundary conditions on the molecular system
and computing time correlation functions of the eigenfunctions of the diffusion
operator corresponding to the same boundary conditions.


title: Structure and energetics of helium adsorption on nanosurfaces

abstract:
  The ground and excited state properties of small helium clusters, 4He_N,
containing nanoscale (~3-10 Angstroms) planar aromatic molecules have been
studied with quantum Monte Carlo methods. Ground state structures and energies
are obtained from importance-sampled, rigid-body diffusion Monte Carlo. Excited
state energies due to helium vibrational motion are evaluated using the
projection operator, imaginary time spectral evolution technique. We examine
the adsorption of N helium atoms (N less than or equal to 24) on a series of
planar aromatic molecules (benzene, naphthalene, anthracene, tetracene,
phthalocyanine). The first layer of helium atoms is well-localized on the
molecule surface, and we find well-defined localized excitations due to
in-plane vibrational motion of helium on the molecule surface. We discuss the
implications of these confined excitations for the molecule spectroscopy.


title: Lagrangian Averaging for Compressible Fluids

abstract:
  This paper extends the derivation of the Lagrangian averaged Euler
(LAE-$\alpha$) equations to the case of barotropic compressible flows. The aim
of Lagrangian averaging is to regularize the compressible Euler equations by
adding dispersion instead of artificial viscosity. Along the way, the
derivation of the isotropic and anisotropic LAE-$\alpha$ equations is
simplified and clarified.
  The derivation in this paper involves averaging over a tube of trajectories
$\eta^\epsilon$ centered around a given Lagrangian flow $\eta$. With this tube
framework, the Lagrangian averaged Euler (LAE-$\alpha$) equations are derived
by following a simple procedure: start with a given action, Taylor expand in
terms of small-scale fluid fluctuations $\xi$, truncate, average, and then
model those terms that are nonlinear functions of $\xi$. Closure of the
equations is provided through the use of \emph{flow rules}, which prescribe the
evolution of the fluctuations along the mean flow.


title:
Cosmic Rays and the Evolution of Earths Climate During the Last 4.6
  Billion Years

abstract:
  Variations in the flux of Galactic Cosmic Rays (GCR) at Earth during the last
4.6 billion years are constructed from information about the Star Formation
Rate (SFR) in the Milky Way and the evolution of solar activity. The variations
of GCR show a remarkable resemblance to changes in Earth's climate during the
period considered, suggesting that Earths climate is closely linked to the
evolution of our Milky Way. The link could be significant in the solution of
the 'faint sun climate paradox'.


title: Optical response of small magnesium clusters

abstract:
  We predict the strong enhancement in the photoabsorption of small Mg clusters
in the region of 4-5 eV due to the resonant excitation of the plasmon
oscillations of cluster electrons. The photoabsorption spectra for neutral Mg
clusters consisting of up to N=11 atoms have been calculated using ab initio
framework based on the time dependent density functional theory (TDDFT). The
nature of predicted resonances has been elucidated by comparison of the results
of the ab initio calculations with the results of the classical Mie theory. The
splitting of the plasmon resonances caused by the cluster deformation is
analysed. The reliability of the used calculation scheme has been proved by
performing the test calculation for a number of sodium clusters and the
comparison of the results obtained with the results of other methods and
experiment.


title:
Near-field enhancement and imaging in double planar polariton-resonant
  structures

abstract:
  It is shown that a system of two coupled planar material sheets possessing
surface mode (polariton) resonances can be used for the purpose of evanescent
field restoration and, thus, for the sub-wavelength near-field imaging. The
sheets are placed in free space so that they are parallel and separated by a
certain distance. Due to interaction of the resonating surface modes
(polaritons) of the sheets an exponential growth in the amplitude of an
evanescent plane wave coming through the system can be achieved. This effect
was predicted earlier for backward-wave (double-negative or Veselago) slab
lenses. The alternative system considered here is proved to be realizable at
microwaves by grids or arrays of resonant particles. The necessary
electromagnetic properties of the resonating grids and the particles are
investigated and established. Theoretical results are supported by microwave
experiments that demonstrate amplification of evanescent modes.


title:
X-ray fluoresced high-Z (up to Z = 82) K-x-rays produced by LiNbO3 and
  LiTaO3 pyroelectric crystal electron accelerators

abstract:
  High-energy bremsstrahlung and K X-rays were used to produce nearly
background-free K X-ray spectra of up to 87 keV (Pb) via X-ray fluorescence.
The fluorescing radiation was produced by electron accelerators, consisting of
heated and cooled cylindrical LiTaO3 and LiNbO3 crystals at mTorr pressures.
The newly discovered process of gas amplification whereby the ambient gas
pressure is optimized to maximize the electron energy was used to produce
energetic electrons which when incident on a W/Bi target gave rise to a
radiation field consisting of high-energy bremsstrahlung as well as W and Bi K
X-rays. These photons were used to fluoresce Ta and Pb K X-rays.


title:
Using molecular similarity to construct accurate semiempirical electron
  structure theories

abstract:
  Ab initio electronic structure methods give accurate results for small
systems, but do not scale well to large systems. Chemical insight tells us that
molecular functional groups will behave approximately the same way in all
molecules, large or small. This molecular similarity is exploited in
semiempirical methods, which couple simple electronic structure theories with
parameters for the transferable characteristics of functional groups. We propse
that high-level calculations on small molecules provide a rich source of
parametrization data. In principle, we can select a functional group, generate
a large amount of ab initio data on the group in various small-molecule
environments, and "mine" this data to build a sophisticated model for the
group's behavior in large molecules. This work details such a model for
electron correlation: a semiempirical, subsystem-based correlation functional
that predicts a subsystem's two-electron density as a functional of its
one-electron density. This model is demonstrated on two small systems: chains
of linear, minimal-basis (H-H)5, treated as a sum of four overlapping (H-H)2
subsystems; and the aldehyde group of a set of HOC-R molecules. The results
provide an initial demonstration of the feasibility of this approach.


title: Statistical Issues in Particle Physics -- A View from BaBar

abstract:
  The statistical methods used in deriving physics results in the BaBar
collaboration are reviewed, with especial emphasis on areas where practice is
not uniform in particle physics.


title: Relative Entropy and Inductive Inference

abstract:
  We discuss how the method of maximum entropy, MaxEnt, can be extended beyond
its original scope, as a rule to assign a probability distribution, to a
full-fledged method for inductive inference. The main concept is the (relative)
entropy S[p|q] which is designed as a tool to update from a prior probability
distribution q to a posterior probability distribution p when new information
in the form of a constraint becomes available. The extended method goes beyond
the mere selection of a single posterior p, but also addresses the question of
how much less probable other distributions might be. Our approach clarifies how
the entropy S[p|q] is used while avoiding the question of its meaning.
Ultimately, entropy is a tool for induction which needs no interpretation.
Finally, being a tool for generalization from special examples, we ask whether
the functional form of the entropy depends on the choice of the examples and we
find that it does. The conclusion is that there is no single general theory of
inductive inference and that alternative expressions for the entropy are
possible.


title:
On the anomalous extreme ultraviolet emission lines in helium-hydrogen
  plasma

abstract:
  The idea of photonic de Broglie waves is discussed in the context of recent
obsrved lines in the helium-hydrogen plasma.


title: On negative streamers: a deterministic approach

abstract:
  In dielectric breakdown, the phenomena of streamers formation and spontaneous
branching is commonly observed. A deterministic negative streamer model is
reviewed in this article. We recently have proposed that this reduced model is
able to explain the branching phenomena, due to a Laplacian instability quite
like in viscous fingering. Particular attention is paid to the physical
interpretation of the model.


title: Study of the atmospheric pressure loading signal in VLBI observations

abstract:
  Redistribution of air masses due to atmospheric circulation causes loading
deformation of the Earth's crust which can be as large as 20 mm for the
vertical component and 3 mm for horizontal components. Rigorous computation of
site displacements caused by pressure loading requires knowledge of the surface
pressure field over the entire Earth surface. A procedure for computing 3-D
displacements of geodetic sites of interest using a 6-hourly pressure field
from the NCEP numerical weather models and the Ponte and Ray [2002] model of
atmospheric tides is presented. We investigated possible error sources and
found that the errors of our pressure loading time series are below the 15%
level. We validated our model by estimating the admittance factors of the
pressure loading time series using a dataset of 3.5 million VLBI observations
from 1980 to 2002. The admittance factors averaged over all sites are 0.95 -+
0.02 for the vertical displacement and 1.00 -+ 0.07 for the horizontal
displacements. For the first time horizontal displacements caused by
atmospheric pressure loading have been detected. The closeness of these
admittance factors to unity allows us to conclude that on average our model
quantitatively agrees with the observations within the error budget of the
model. At the same time we found that the model is not accurate for several
stations which are near a coast or in mountain regions. We conclude that our
model is suitable for routine data reduction of space geodesy observations.


title: Rules for Minimal Atomic Multipole Expansion of Molecular Fields

abstract:
  A non-empirical minimal atomic multipole expansion (MAME) defines atomic
charges or higher multipoles that reproduce electrostatic potential outside
molecules. MAME eliminates problems associated with redundancy and with
statistical sampling, and produces atomic multipoles in line with chemical
intuition.

categories: physics.chem-ph physics.atm-clus physics.bio-ph physics.comp-ph


title:
Status Report on Multi-Cell Superconducting Cavity Development for
  Medium-Velocity Beams

abstract:
  Three prototype 6-cell superconducting cavities for acceleration in the
velocity range of 0.40 to 0.53 times the speed of light have been fabricated.
The quality factor (Q) of the first prototype cavity was above 1E10 for
accelerating gradients up to 11 MV/m. The highest gradient reached was about 16
MV/m; the Q was about 3E9 at the maximum gradient.


title: An Empirical Charge Transfer Potential with Correct Dissociation Limits

abstract:
  The empirical valence bond (EVB) method [J. Chem. Phys. 52, 1262 (1970)] has
always embodied charge transfer processes. The mechanism of that behavior is
examined here and recast for use as a new empirical potential energy surface
for large-scale simulations. A two-state model is explored. The main features
of the model are: (1) Explicit decomposition of the total system electron
density is invoked; (2) The charge is defined through the density decomposition
into constituent contributions; (3) The charge transfer behavior is controlled
through the resonance energy matrix elements which cannot be ignored; and (4) A
reference-state approach, similar in spirit to the EVB method, is used to
define the resonance state energy contributions in terms of "knowable"
quantities. With equal validity, the new potential energy can be expressed as a
nonthermal ensemble average with a nonlinear but analytical charge dependence
in the occupation number. Dissociation to neutral species for a gas-phase
process is preserved. A variant of constrained search density functional theory
is advocated as the preferred way to define an energy for a given charge.


title: WALTA school-network cosmic ray detectors

abstract:
  The Washington Area Large-scale Time coincidence Array (WALTA) is placing
particle detector arrays in secondary schools in the Seattle area to build up a
large-scale ultra-high energy cosmic ray detector network, one of several such
projects around the world. Scintillation counters salvaged from the CASA
experiment in cooperation with the CROP group at the University of Nebraska at
Lincoln are refurbished by teachers and students, tested, calibrated, and
installed in four-fold arrays at high school sites. To identify time
coincidences, a GPS time synchronization system is employed. Data are acquired
using a custom lowcost data acquisition card. Here we will describe the
logistics of WALTA and show samples of data taken with a prototype array at the
University of Washington.


title:
Cylindrical Symmetry Discrimination of Magnetoelectric Optical
  Systematic Effects in a Pump-probe Atomic Parity Violation Experiment

abstract:
  A pump-probe atomic parity violation (APV) experiment performed in a
longitudinal electric field, provides a signal breaking mirror symmetry while
preserving the cylindrical symmetry of the set-up. The excited vapor acts on
the probe beam as a linear dichroic amplifier, imprinting a very specific
signature on the detected signal. Our differential polarimeter is oriented to
yield a null result unless the excited atoms are endowed with a chirality of
some kind. Ideally, only the APV (E-odd) and the calibration (E-even) signals
contribute to a chiral atomic response, a situation highly favourable to the
detection of a tiny effect. In the present work we give a thorough analysis of
possible unwanted defects like stray transverse fields or misalignments which
would spoil the ideal set-up and lead to chiral systematics. A possible way to
suppress such effects is to perform global rotations of the experiment by
incremental steps of 45 degrees, leaving both stray fields and misalignments
unaltered. The conspiration of at least two defects is necessary to affect the
E-odd polarimeter signal. The transverse nature of the defects manifests itself
by an azimuthal cosine square modulation. The harmful systematics are those
which survive the averaging over four successive configurations. They require
the presence of a stray transverse electric field, which can be determined and
eventually minimized by auxiliary measurements of the systematic effects,
amplified by applying a known external magnetic field. Transverse stray
magnetic fields must be compensated by a similar procedure. We also propose
statistical correlation tests as diagnoses of the aforementioned systematic
effects.


title: Highly Nonlinear Dynamics of Third-Harmonic Generation by Focused Beams

abstract:
  Beams that experience third-harmonic generation (THG) also experience Kerr
effects. With Kerr effects, beams do not take simple Gaussian shapes, but
exhibit nonlinear dynamics. These nonlinear dynamics have an effect on the THG
accumulated by focusing and then diverging beams. We formulate a
self-consistent and complete set of nonlinear Schroedinger equations for a pair
of coupled beams -- a fundamental and its third-harmonic. Numerical simulations
show that the Kerr nonlinearities allow some third-harmonic to propagate to the
far-field even for zero or negative phase-mismatch. This is because the
nonlinear dynamics break the beams' reflection symmetry about the focal plane
and therefore increases far-field THG by changing some of the interference from
destructive to constructive. THG conversion efficiencies are computed as
functions of several beam parameters.


title:
Lifetime measurement of the metastable 3d 2D5/2 state in the 40Ca+ ion
  using the shelving technique on a few-ion string

abstract:
  We present a measurement of the lifetime of the metastable 3d 2D5/2 state in
the 40Ca+ ion, using the so-called shelving technique on a string of five
Doppler laser-cooled ions in a linear Paul trap. A detailed account of the data
analysis is given, and systematic effects due to unwanted excitation processes
and collisions with background gas atoms are discussed and estimated. From a
total of 6805 shelving events, we obtain a lifetime
tau=1149+/-14(stat.)+/-4(sys.)ms, a result which is in agreement with the most
recent measurements.


title: Realization of Maxwell's Hypothesis

abstract:
  Two similar and parallel Ag-O-Cs surfaces in a vacuum tube ceaselessly eject
electrons at room temperature. A static magnetic field applied to the tube
plays the role of 'Maxwell's demon'. The thermal electrons are so controlled by
the magnetic field that they can travel only from one Ag-O-Cs surface to the
other, resulting in collections of positive and negative charge on the two
surfaces, respectively, as well as an electric potential between the two
surfaces. A load, a resistance outside of the tube for example, is connected by
wires to the two surfaces, continuously receiving electric power from the tube.
The ambient air is a single heat reservoir in this situation, and all of the
heat extracted by the tube from the air is converted to electric energy,
without producing any other effect. The authors believe that the experiment is
in contradiction to Kelvin's statement, and that the famous hypothesis proposed
by Maxwell about 140 years ago is realized.


title: Introduction to Statistical Issues in Particle Physics

abstract:
  An account is given of the methods of working of Experimental High Energy
Particle Physics, from the viewpoint of statisticians and others unfamiliar
with the field. Current statistical problems, techniques, and hot topics are
introduced and discussed.


title:
Small-core photonic crystal fibers with weakly disordered air-hole
  claddings

abstract:
  Motivated by recent experimental work by Folkenberg et al. we consider the
effect of weak disorder in the air-hole lattice of small-core photonic crystal
fibers. We find that the broken symmetry leads to higher-order modes which have
generic intensity distributions resembling those found in standard fibers with
elliptical cores. This explains why recently reported experimental higher-order
mode profiles appear very different from those calculated numerically for ideal
photonic crystal fibers with inversion and six-fold rotational symmetry. The
splitting of the four higher-order modes into two groups fully correlates with
the observation that these modes have different cut-offs.


title: The energy conservation law in classical electrodynamics 2

abstract:
  A logical error in the usual derivation of the energy conservation law is
analyzed, and a way to avoid the error is presented.


title:
Student Conceptions of Holography (Schuelervorstellungen zur
  Holographie)

abstract:
  In a lesson on holography a tension is to be found between the ray model, the
wave model, the phasor model and the particle model. Lessons depend on the
previous experiences of the students, the intentions of the teacher as well as
on other parameters and therefore provide a diversity in emphasis while
explaining holographic effects. As class discussion concerning selected areas
of interference optics and specifically holography develops in a questioning
manner and with limited intervention from the teacher, numerous student
conceptions with regard to interference optics and different model conceptions
of light can be identified. Student interviews in which these discovered
concepts are explored in greater detail can provide in depth information.
Primary student conceptions, which were gathered in the main research conducted
for a dissertation project will be presented here and analysed with a view to
their didactic consequences.


title: Rearrangement of cluster structure during fission processes

abstract:
  Results of molecular dynamics simulations of fission reactions $Na_{10}^{2+}
\to Na_7^+ + Na_3^+$ and $Na_{18}^{2+} \to 2 Na_9^+$ are presented. Dependence
of the fission barriers on isomer structure of the parent cluster is analyzed.
It is demonstrated that the energy necessary for removing homothetic groups of
atoms from the parent cluster is largely independent of the isomer form of the
parent cluster. Importance of rearrangement of the cluster structure during the
fission process is elucidated. This rearrangement may include transition to
another isomer state of the parent cluster before actual separation of the
daughter fragments begins and/or forming a "neck" between the separating
fragments.


title:
Dosimetry characterization of $^{32}$P intravascular brachytherapy
  source wires using Monte Carlo codes PENELOPE and GEANT4

abstract:
  Monte Carlo calculations using the codes PENELOPE and GEANT4 have been
performed to characterize the dosimetric parameters of the new 20 mm long
catheter based $^{32}$P beta source manufactured by Guidant Corporation. The
dose distribution along the transverse axis and the two dimensional dose rate
table have been calculated. Also, the dose rate at the reference point, the
radial dose function and the anisotropy function were evaluated according to
the adapted TG-60 formalism for cylindrical sources. PENELOPE and GEANT4 codes
were first verified against previous results corresponding to the old 27 mm
Guidant $^{32}$P beta source. The dose rate at the reference point for the
unsheathed 27 mm source in water was calculated to be $0.215 \pm 0.001$ cGy
s$^{-1}$ mCi$^{-1}$, for PENELOPE, and $0.2312 \pm 0.0008$ cGy s$^{-1}$
mCi$^{-1}$, for GEANT4. For the unsheathed 20 mm source these values were
$0.2908 \pm 0.0009$ cGy s$^{-1}$ mCi$^{-1}$ and $0.311 \pm 0.001$ cGy s$^{-1}$
mCi$^{-1}$, respectively. Also, a comparison with the limited data available on
this new source is shown. We found non negligible differences between the
results obtained with PENELOPE and GEANT4.


title:
Raining lead around 250mya : a smoking gun for an Australian impact
  origin of the Permian Extinction

abstract:
  Recent documentation of extreme atmospheric sulfur and methane contents at
the time of the vast Permo-Triassic (P-T) extinction makes it possible to
interpret an observation that has lain unnoticed in the geological literature
for 40 years. This is the finding of microscopic metallic lead tear drops in
the fluvial strata of the early Triassic sandstones that overlie Permian coal
beds and other sedimentary deposits in the Sydney basin of Australia. Elemental
lead is almost unknown in nature, so its occurrence in these graphite-loaded
sandstones is a provocative finding. While climate change and vulcanism could
explain the carbon and sulfur anomalies, the only way to account for metallic
lead aerodynamic droplets is by massive impact and vaporization of lead
mineral-containing formations. Since lead occurs geologically as the sulfide
and since lead is an easily reduced element, its occurrence in conjunction with
sulfur and carbon count anomalies suggests a bolide impact on carbon-loaded
strata in a sulfide mineral-rich region. From these clues, and from stream
cross-bedding data, we identify a probable site for the impact, in Bass Strait
between Tasmania and Victoria. A gravitational anomaly, similar to that known
at the site of the Cretacious-Tertiary (C-T) impact site, conforms with a
central uplift. The sudden compression at an Australian impact site would
provoke tension fissuring on the opposite side of a shell- structured planet,
hence is consistent with the unprecedented flood basalts initiated in Siberia
at the P-T boundary. Our interpretation requires that lead microspheres and
graphite occur together elsewhere, possibly in Antarctic sandstones.


title:
Bias in the temperature of helium nanodroplets measured by an embedded
  rotor

abstract:
  The ro--vibrational spectra of molecules dissolved in liquid $^4$He
nanodroplets display rotational structure. Where resolved, this structure has
been used to determine a temperature that has been assumed to equal that of the
intrinsic excitations of the helium droplets containing the molecules.
Consideration of the density of states as a function of energy and total
angular momentum demonstrates that there is a small but significant bias of the
rotor populations that make the temperature extracted from a fit to its
rotational level populations slightly higher than the temperature of the
ripplons of the droplet. This bias grows with both the total angular momentum
of the droplet and with the moment of inertia of the solute molecule.


title:
Photon trajectories in incoherent atomic radiation trapping as Levy
  flights

abstract:
  Photon trajectories in incoherent radiation trapping for Doppler, Lorentz and
Voigt line shapes under complete frequency redistribution are shown to be Levy
flights. The jump length (r) distributions display characteristic long tails.
For the Lorentz line shape, the asymptotic form is a strict power-law r^{-3/2}
while for Doppler the asymptotic is r^{-2} (ln r)^{-1/2}. For the Voigt
profile, the asymptotic form has always a Lorentz character, but the trajectory
is a self-affine fractal with two characteristic Hausdorff scaling exponents.


title: Astronomy and the Fall of Babylon

abstract:
  This illustrated article represents a popular account of the study of the
Babylonian astronomical records of Enuma Anu Enlil tablet series i.e. of the
Venus Tablet of Ammisaduqa and of two lunar eclipses linked with the IIIrd
dynasty of Ur, having resulted in the proposal of Ultra-Low chronology of the
Near East in II millennium B.C. The emerged Ultra-Low chronology is by 96 years
shorter than the conventional Middle chronology and by now is supported by
various independent studies. Tables of relative chronologies of principal
kingdoms of Mesopotamia are given, along with some dates associated with the
fall of Babylon in II millennium B.C. The technical details are given in the
book by H.Gasche, J.A.Armstrong, S.W.Cole and V.G.Gurzadyan, "Dating the Fall
of Babylon" (Mesopotamian History and Environment, Series II, University of
Ghent and Chicago Press, 1998) and in subsequent articles.


title: Ray splitting in paraxial optical cavities

abstract:
  We present a numerical investigation of the ray dynamics in a paraxial
optical cavity when a ray splitting mechanism is present. The cavity is a
conventional two-mirror stable resonator and the ray splitting is achieved by
inserting an optical beam splitter perpendicular to the cavity axis. We show
that depending on the position of the beam splitter the optical resonator can
become unstable and the ray dynamics displays a positive Lyapunov exponent.


title: Cluster emission under femtosecond laser ablation of silicon

abstract:
  Rich populations of clusters have been observed after femtosecond laser
ablation of bulk silicon in vacuum. Size and velocity distributions of the
clusters as well as their charge states have been analyzed by reflectron
time-of-flight mass spectrometry. An efficient emission of both neutral silicon
clusters Sin (up to n = 6) and their cations Sin+ (up to n = 10) has been
observed. The clusters are formed even at very low laser fluences, below
ablation threshold, and their relative yield increases with fluence. We show
the dependencies of the cluster yield as well as the expansion dynamics on both
laser wavelength and laser fluence. The mechanisms of the cluster formation are
discussed.

categories: physics.atm-clus cond-mat.mtrl-sci physics.chem-ph physics.plasm-ph


title:
Laser ablation synthesis of zinc oxide clusters: a new family of
  fullerenes?

abstract:
  Positively charged zinc oxide clusters ZnnOm (up to n = 16, m <= n) of
various stoichiometry were synthesized in the gas phase by excimer ArF laser
ablation of a ZnO target and investigated using time-of-flight mass
spectrometry. Depending on ablation conditions, either metal rich or
stoichiometric clusters dominate in the mass spectrum. When the irradiated
target surface is fairly fresh, the most abundant clusters are metal rich with
Zn(n+1)On and Zn(n+3)On being the major series. The stoichiometric clusters are
observed with an etched ablated surface. The magic numbers at n = 9, 11 and 15
in mass spectra of (ZnO)n clusters indicate that the clusters have hollow
spheroid structures related to fullerenes. A local abundance minimum at n = 13
provides an additional evidence for the presence in the ablation plume of
fullerene-like (ZnO)n clusters.


title:
A New Method of Measuring 81Kr and 85Kr Abundances in Environmental
  Samples

abstract:
  We demonstrate a new method for determining the 81Kr/Kr ratio in
environmental samples based upon two measurements: the 85Kr/81Kr ratio measured
by Atom Trap Trace Analysis (ATTA) and the 85Kr/Kr ratio measured by Low-Level
Counting (LLC). This method can be used to determine the mean residence time of
groundwater in the range of 10^5 - 10^6 a. It requires a sample of 100 micro-l
STP of Kr extracted from approximately two tons of water. With modern
atmospheric Kr samples, we demonstrate that the ratios measured by ATTA and LLC
are directly proportional to each other within the measurement error of +/-
10%; we calibrate the 81Kr/Kr ratio of modern air measured using this method;
and we show that the 81Kr/Kr ratios of samples extracted from air before and
after the development of the nuclear industry are identical within the
measurement error.


title:
LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter
  Prototype

abstract:
  We report on the performance of a monitoring system for a prototype
calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled
with photomultiplier tubes. The tests were carried out at the 70 GeV
accelerator complex at Protvino, Russia.


title: Boltzmann's H-theorem and time irreversibility

abstract:
  It is shown that the justification of the Boltzman H-theorem needs more than
just the assumption of molecular chaos and the picture of time irreversibility
related to it should be reinvestigated.


title: Laser Spectroscopic Measurement of Helium Isotope Ratios

abstract:
  A sensitive laser spectroscopic method has been applied to the quantitative
determination of the isotope ratio of helium at the level of 3He/4He = 10^-7 -
10^-5. The resonant absorption of 1083 nm laser light by the metastable 3He
atoms in a discharge cell was measured with the frequency modulation saturation
spectroscopy technique while the abundance of 4He was measured by a direct
absorption technique. The results on three different samples extracted from the
atmosphere and commercial helium gas were in good agreement with values
obtained with mass spectrometry. The achieved 3-sigma detection limit of 3He in
helium is 4 x 10^-9. This demonstration required a 200 micro-L STP sample of
He. The sensitivity can be further improved, and the required sample size
reduced, by several orders of magnitude with the addition of cavity enhanced
spectroscopy.


title: Analysis on the imaging properties of a left-handed material slab

abstract:
  We investigate in this paper the imaging properties of an absorptive
left-handed material (LHM) slab. For a line source, a geometric explanation to
the reason of the thickness limitation on an ideal slab is given. For a lossy
slab, the imaging properties are determined by the wavelength, the slab
thickness, the distance from the source to the nearer boundary of the slab, and
the absorption effect. Varying the ratios between these quantities, the image
width can be changed from wavelength to subwavelength scale. In the former
situation, the energy density is mainly concentrated at the two image spots. In
the later case, though image of subwavelength width appears on the focal plane,
however, most energy is located at about the two boundaries of the slab, and
beyond the boundaries the wave amplitude decays exponentially. The relations
between the subwavelength imaging and uncertainty principle is also discussed.


title:
Stability of leap-frog constant-coefficients semi-implicit schemes for
  the fully elastic system of Euler equations. Flat-terrain case

abstract:
  The aim of this paper is to investigate the response of this system/scheme in
terms of stability in presence of explicitly treated residual terms, as it
inevitably occurs in the reality of NWP. This sudy is restricted to the impact
of thermal and baric residual terms (metric residual terms linked to the
orography are not considered here). It is shown that conversely to what occurs
with Hydrostatic Primitive Equations, the choice of the prognostic variables
used to solve the system in time is of primary importance for the robustness
with Euler Equations. For an optimal choice of prognostic variables,
unconditionnally stable schemes can be obtained (with respect to the length of
the time-step), but only for a smaller range of reference states than in the
case of Hydrostatic Primitive Equations. This study also indicates that: (i)
vertical coordinates based on geometrical height and on mass behave similarly
in terms of stability for the problems examined here, and (ii) hybrid
coordinates induce an intrinsic instability, the practical importance of which
is however not completely elucidated in the theoretical context of this paper.


title:
On the Use of a Wider Class of Linear Systems for the Design of
  Constant-Coefficients Semi-Implicit Time-Schemes in NWP

abstract:
  The linearization of the meteorological equations around a specified
reference state, usually applied in NWP to define the linear system of
constant-coefficients semi-implicit schemes, is outlined as an unnecessarily
restrictive approach which may be detrimental in terms of stability. It is
shown theoretically that an increased robustness can sometimes be obtained by
choosing the reference linear system in a wider set of possibilities. The
potential benefits of this new approach are illustrated in two simple examples.
The advantage in robustness is not obtained at the price of an increased error
or complexity.


title:
Observation of near-critical reflection of internal waves in a stably
  stratified fluid

abstract:
  An experimental study is reported of the near-critical reflection of internal
gravity waves over sloping topography in a stratified fluid. An overturning
instability close to the slope and triggering the boundary-mixing process is
observed and characterized. These observations are found in good agreement with
a recent nonlinear theory.


title: Quantum corrected electron holes

abstract:
  The theory of electron holes is extended into the quantum regime. The
Wigner--Poisson system is solved perturbatively based in lowest order on a
weak, standing electron hole. Quantum corrections are shown to lower the
potential amplitude and to increase the number of deeply trapped electrons.
They, hence, tend to bring this extreme non--equilibrium state closer to
thermodynamic equilibrium, an effect which can be attributed to the tunneling
of particles in this mixed state system.


title:
Eigenvector Expansion and Petermann Factor for Ohmically Damped
  Oscillators

abstract:
  Correlation functions $C(t) \sim <\phi(t)\phi(0)>$ in ohmically damped
systems such as coupled harmonic oscillators or optical resonators can be
expressed as a single sum over modes $j$ (which are not power-orthogonal), with
each term multiplied by the Petermann factor (PF) $C_j$, leading to "excess
noise" when $|C_j| > 1$. It is shown that $|C_j| > 1$ is common rather than
exceptional, that $|C_j|$ can be large even for weak damping, and that the PF
appears in other processes as well: for example, a time-independent
perturbation $\sim\ep$ leads to a frequency shift $\sim \ep C_j$. The
coalescence of $J$ ($>1$) eigenvectors gives rise to a critical point, which
exhibits "giant excess noise" ($C_j \to \infty$). At critical points, the
divergent parts of $J$ contributions to $C(t)$ cancel, while time-independent
perturbations lead to non-analytic shifts $\sim \ep^{1/J}$.


title:
Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental
  Constants

abstract:
  In 2003 we have measured the absolute frequency of the $(1S, F=1, m_F=\pm 1)
\leftrightarrow (2S, F'=1, m_F'=\pm 1)$ two-photon transition in atomic
hydrogen. We observed a variation of $(-29\pm 57)$ Hz over a 44 months interval
separating this measurement from the previous one performed in 1999. We have
combined this result with recently published results of optical transition
frequency measurement in the $^{199}$Hg$^+$ ion and and comparison between
clocks based on $^{87}$Rb and $^{133}$Cs. From this combination we deduce the
stringent limits for fractional time variation of the fine structure constant
$\partial/{\partial t}(\ln \alpha)=(-0.9\pm 4.2)\times 10^{-15}$ yr$^{-1}$ and
for the ratio of $^{87}$Rb and $^{133}$Cs spin magnetic moments
$\partial/{\partial t}(\ln[\mu_{\rm {Rb}}/\mu_{\rm {Cs}}])=(0.5\pm 2.1)\times
10^{-15}$ yr$^{-1}$. This is the first precise restriction for the fractional
time variation of $\alpha$ made without assumptions about the relative drifts
of the constants of electromagnetic, strong and weak interactions.


title: Crosstalk between beam-beam effects and lattice nonlinearities in DAPhNE

abstract:
  Numerical simulations of beam-beam effects in the electron-positron
Phi-factory DAPhNE taking into account the measured cubic nonlinearities have
shown that the nonlinearities have a strong impact on the collider luminosity
performance. The numerical results explain many of experimental observations
made during collisions in both single and multibunch regimes.


title: Simulation of induction at low magnetic Prandtl number

abstract:
  We consider the induction of magnetic field in flows of electrically
conducting fluid at low magnetic Prandtl number and large kinetic Reynolds
number. Using the separation between the magnetic and kinetic diffusive
lengthscales, we propose a new numerical approach. The coupled magnetic and
fluid equations are solved using a mixed scheme, where the magnetic field
fluctuations are fully resolved and the velocity fluctuations at small scale
are modelled using a Large Eddy Simulation (LES) scheme. We study the response
of a forced Taylor-Green flow to an externally applied field: tology of the
mean induction and time fluctuations at fixed locations. The results are in
remarkable agreement with existing experimental data; a global $1/f$ behavior
at long times is also evidenced.


title: Coulomb crystallization in expanding laser-cooled neutral plasmas

abstract:
  We present long-time simulations of expanding ultracold neutral plasmas,
including a full treatment of the strongly coupled ion dynamics. Thereby, the
relaxation dynamics of the expanding laser-cooled plasma is studied, taking
into account elastic as well as inelastic collisions. It is demonstrated that,
depending on the initial conditions, the ionic component of the plasma may
exhibit short-range order or even a superimposed long-range order resulting in
concentric ion shells. In contrast to ionic plasmas confined in traps, the
shell structures are built up from the center of the plasma cloud rather than
from the periphery.


title: Recoil-induced lasing

abstract:
  The interaction of an atomic gas confined inside a cavity with a strong
electromagnetic field is numerically and theoretically investigated in a regime
where recoil effects are not negligible. The spontaneous appearance of a
density grating (atomic bunching) accompanied by the onset of coherent
backpropagation is found to be ruled by a continuous phase-transition.
Numerical tests allow us to convincingly prove that the transition is steered
by the appearence of a periodic atomic density modulation. Consideration of
different experimental relaxation mechanisms induces us to analyze the problem
in nearly analytic form, in the large detuning limit, using both a Vlasov
approach and a Fokker-Planck description. The application of our predictions to
recent experimental findings, reported in [Phys. Rev. Lett. {\bf 91}, 183601
(2003)], yields a semi-quantitative agreement with the observations.


title:
Experimental investigation of coherent Smith-Purcell radiation from a
  "flat" grating

abstract:
  Using the pre-bunched electron beam of 5-MeV linear accelerator the coherent
Smith-Purcell radiation (CSPR) from a flat periodic target (made of conductive
layers separated by dielectric gaps) in millimeter wavelength region has been
investigated. The angular distribution of this radiation was measured with a
narrow-band detector and experimental data agree with our theoretical
calculations for similar kind of targets. Such properties of Smith-Purcell
radiation as strong dependence of radiation wavelength on the observation angle
overlapping with coherent radiation effect may be used for a noninvasive bunch
length measurement. The possibility of using the room temperature detectors for
single bunch measurements is demonstrated.


title: The Subgrid Problem of the Thermal Convection in the Earth's Liquid Core

abstract:
  The problem of the turbulent thermal convection in the Earth's liquid core is
considered. Following assumptions on decreasing of the spatial scales due to
the rapid rotation, we propose the subgrid model of the eddy diffusivity, which
is used in the large-scale model. This approach makes it possible to model
realistic regimes with small Ekman and Rossby numbers ($E\sim 10^{-14}$, $R_o
\sim 10^{-8}$) and a sufficiently large Rayleigh number $R_a \sim 10^{12}$. The
obtained estimate of the averaged kinetic energy is comparable with
observations. The model includes rotation of the solid core due to the viscous
torque.


title:
Neutron reflection from condensed matter, the Goos-H\"anchen effect and
  coherence

abstract:
  The Goos-H\"anchen (G-H) effect for neutron reflection from condensed matter
is considered. An experiment to quantify the effect is proposed. The relation
of G-H shift to the neutron coherence length is considered.


title:
Extremely asymmetrical scattering of electromagnetic waves in gradually
  varying periodic arrays

abstract:
  This paper analyses theoretically and numerically the effect of varying
grating amplitude on the extremely asymmetrical scattering (EAS) of bulk and
guided optical modes in non-uniform strip-like periodic Bragg arrays with
stepwise and gradual variations in the grating amplitude across the array. A
recently developed new approach based on allowance for the diffractional
divergence of the scattered wave is used for this analysis. It is demonstrated
that gradual variations in magnitude of the grating amplitude may change the
pattern of EAS noticeably but not radically. On the other hand, phase
variations in the grating may result in a radically new type of Bragg
scattering - double-resonant EAS (DEAS). In this case, a combination of two
strong simultaneous resonances (one with respect to frequency, and another with
respect to the phase variation) is predicted to take place in non-uniform
arrays with a step-like phase and gradual magnitude variations of the grating
amplitude. The tolerances of EAS and DEAS to small gradual variations in the
grating amplitude are determined. The main features of these types of
scattering in non-uniform arrays are explained by the diffractional divergence
of the scattered wave inside and outside the array.


title: Depolarization induced by subwavelength metal hole arrays

abstract:
  We present a symmetry-based theory of the depolarization induced by
subwavelength metal hole arrays. We derive the Mueller matrices of hole arrays
with various symmetries (in particular square and hexagonal) when illuminated
by a finite-diameter (e.g. gaussian) beam. The depolarization is due to a
combination of two factors: (i) propagation of surface plasmons along the
surface of the array, (ii) a spread of wave vectors in the incident beam.


title:
Notes on a possible phenomenology of internal transport barriers in
  tokamak

abstract:
  We propose a new phenomenology of the generation of internal transport
barriers, based on the exact periodic solution of the Flierl-Petvishvili
equation. We examine the stability of this solution and compare the late stages
of the flow with the ensemble of vortices.


title: Interactions between Zero-Point Radiation and Electrons

abstract:
  Knowing the magnitude of the energy flow inherent to zero-point radiation
allows us to approach the question of its possible interaction with particles
of matter. Its photons are not different from the rest, and must in principle
be subject to the Compton effect and the Klein-Nishima-Tann formula for its
cross section. On this assumption, it is shown here that zero-point radiation
may be powerful enough to explain Poincar\'e's tensions and to supply an
efficient cause for gravitation. This could be only the case if the classic
radius of the electron measures $8.143375\times10^{20}q_\la$, where $q_\la$ is
the minimum wavelength for electromagnetic radiation, and if the wavelength of
the most energetic photon in the actual zero-point radiation is
$5.275601\times10^{27}q_\la$. To the first of these numbers there corresponds
the energy $3.5829 \times10^{23}$ MeV for the photon whose wavelength is
$1q_\la$. This gives also the relation $q_\la=(2 \pi \al)^{1/2}L_P$, where
$L_P$ is the Planck Length. Finally the relation between the force of gravity
and the electrostatic force is explained by the equations obtained in this
paper.


title: Chaotic ray dynamics in an optical cavity with a beam splitter

abstract:
  We investigate the ray dynamics in an optical cavity when a ray splitting
mechanism is present. The cavity is a conventional two-mirror stable resonator
and the ray splitting is achieved by inserting an optical beam splitter
perpendicular to the cavity axis. Using Hamiltonian optics, we show that such a
simple device presents a surprisingly rich chaotic ray dynamics.


title:
Simple and Accurate Computations of Solvatochromic Shifts in pi -> pi*
  Transitions of Aromatic Chromophors

abstract:
  A new approach is introduced for calculating the spectral shifts of the most
bathochromic pi -> pi* transition of an aromatic chromophore in apolar
environments. As an example, perylene in solid and liquid n-alkane matrices was
chosen, and all shifts are calculated relative to one well-defined
solid-inclusion system. It is shown that a simple two-level treatment of the
solute using Huckel theory yields spectral shifts in excellent agreement with
experimental results for the most prominent inclusion sites of perylene in
solid n-alkane surroundings and for the dilute solutions in liquid n-alkanes.
The idea is general enough to be applied to any aromatic chromophore in a
nonpolar solvent matrix. In contrast to earlier treatments, this approach is
based on geometry-dependent polarizabilities, employs a r^-4 dependence for the
dispersion energy, is conceptually simple and computationally efficient.
Different simple models based on our general approach to compute the UV
spectral shifts due to solvation indicate that the dispersive part of the
van-der-Waals energy, which stabilizes the LUMO of perylene more than the HOMO,
falls off with a distance dependence of r^-4 in a range up to ~1 nm and not as
r^-6, as has been assumed for a long time. This finding corresponds to the
interpretation of temporary dipoles as being equivalent to weak permanent
dipoles with fluctuating orientation.


title: Dressed-state approach to a simple radiating atom

abstract:
  We consider a system consisting of an atom in the dipole approximation,
coupled to the electromagnetic field. Using recently introduced renormalized
coordinates and dressed states, we give a non-perturbative solution to the atom
radiation process. From this formalism a non-exponential decay law naturally
emerges. However, at least for low frequencies and weak coupling, there is only
a very small, practically non-detectable, deviation from a purely exponential
decay, in agreement with all previous results in the literature.


title: The gap-tooth scheme for homogenization problems

abstract:
  An important class of problems exhibits smooth behaviour in space and time on
a macroscopic scale, while only a microscopic evolution law is known. For such
time-dependent multi-scale problems, an ``equation-free framework'' has been
proposed, of which the gap-tooth scheme is an essential component. The
gap-tooth scheme is designed to approximate a time-stepper for an unavailable
macroscopic equation in a macroscopic domain; it uses appropriately initialized
simulations of the available microscopic model in a number of small boxes,
which cover only a fraction of the domain. We analyze the convergence of this
scheme for a parabolic homogenization problem with non-linear reaction. In this
case, the microscopic model is a partial differential equation with rapidly
oscillating coefficients, while the unknown macroscopic model is approximated
by the homogenized equation. We show that our method approximates a finite
difference scheme of arbitrary (even) order for the homogenized equation when
we appropriately constrain the microscopic problem in the boxes. We illustrate
this theoretical result with numerical tests on several model problems. We also
demonstrate that it is possible to obtain a convergent scheme without
constraining the microscopic code, by introducing buffer regions around the
computational boxes.


title: The Structure of Positive Decompositions of Exponential Operators

abstract:
  The solution of many physical evolution equations can be expressed as an
exponential of two or more operators acting on initial data. Accurate solutions
can be systematically derived by decomposing the exponential in a product form.
For time-reversible equations, such as the Hamilton or the Schr\"odinger
equation, it is immaterial whether or not the decomposition coefficients are
positive. In fact, most symplectic algorithms for solving classical dynamics
contain some negative coefficients. For time-irreversible systems, such as the
Fokker-Planck equation or the quantum statistical propagator, only
positive-coefficient decompositions, which respect the time-irreversibility of
the diffusion kernel, can yield practical algorithms. These positive time steps
only, forward decompositions, are a highly effective class of factorization
algorithms. This work introduce a framework for understanding the structure of
these algorithms. By a suitable representation of the factorization
coefficients, we show that specific error terms and order conditions can be
solved {\it analytically}. Using this framework, we can go beyond the
Sheng-Suzuki theorem and derive a lower bound for the error coefficient
$e_{VTV}$. By generalizing the framework perturbatively, we can further prove
that it is not possible to have a sixth order forward algorithm by including
only the commutator $[VTV]\equiv[V,[T,V]]$. The pattern of these higher order
forward algorithms is that in going from the (2n)$^{\rm th}$ to the
(2n+2)$^{\rm th}$ order, one must include a new commutator $[VT^{2n-1}V]$ in
the decomposition process.


title:
Hyperfine quenching of the metastable $^3P_{0,2}$ states in divalent
  atoms

abstract:
  Hyperfine quenching rates of the lowest-energy metastable $^3P_0$ and $^3P_2$
states of Mg, Ca, Sr, and Yb atoms are computed. The calculations are carried
out using ab initio relativistic many-body methods. The computed lifetimes may
be useful for designing novel ultra-precise optical clocks and trapping
experiments with the $3P_2$ fermionic isotopes. The resulting natural widths of
the $^3P_0 -> ^1S_0$ clock transition are 0.44 mHz for $^{25}$Mg, 2.2 mHz for
$^{43}$Ca, 7.6 mHz for $^{87}$Sr, 43.5 mHz for $^{171}$Yb, and 38.5 mHz for
$^{173}$Yb. Compared to the bosonic isotopes, the lifetime of the $3P_2$ states
in fermionic isotopes is noticeably shortened by the hyperfine quenching but
still remains long enough for trapping experiments.


title: Mechanical effects of optical vortices

abstract:
  We concentrate on the forces and torques exerted on transparent and absorbing
particles trapped in laser beams containing optical vortices. We review
previous theoretical and experimental work and then present new calculations of
the effect of vortex beams on absorbing particles.


title:
Electron impact double ionization of helium from classical trajectory
  calculations

abstract:
  With a recently proposed quasiclassical ansatz [Geyer and Rost, J. Phys. B 35
(2002) 1479] it is possible to perform classical trajectory ionization
calculations on many electron targets. The autoionization of the target is
prevented by a M\o{}ller type backward--forward propagation scheme and allows
to consider all interactions between all particles without additional
stabilization. The application of the quasiclassical ansatz for helium targets
is explained and total and partially differential cross sections for electron
impact double ionization are calculated. In the high energy regime the
classical description fails to describe the dominant TS1 process, which leads
to big deviations, whereas for low energies the total cross section is
reproduced well. Differential cross sections calculated at 250 eV await their
experimental confirmation.


title:
Position Dependence of Charge Collection in Prototype Sensors for the
  CMS Pixel Detector

abstract:
  This paper reports on the sensor R&D activity for the CMS pixel detector.
Devices featuring several design and technology options have been irradiated up
to a proton fluencec of 1E15 n_eq/cm**2 at the CERN PS. Afterward they were
bump bonded to unirradiated readout chips and tested using high energy pions in
the H2 beam line of the CERN SPS. The readout chip allows a non zero suppressed
full analogue readout and therefore a good characterization of the sensors in
terms of noise and charge collection properties. The position dependence of
signal is presented and the differences between the two sensor options are
discussed.


title:
Self-organization in a simple model of adaptive agents playing 2X2 games
  with arbitrary payoff matrices

abstract:
  We analyze, both analytically and numerically, the self-organization of a
system of "selfish" adaptive agents playing an arbitrary iterated pairwise game
(defined by a 2X2 payoff matrix). Examples of possible games to play are: the
Prisoner's Dilemma (PD) game, the Chicken game, the Hero game, etc. The agents
have no memory, use strategies not based on direct reciprocity nor 'tags' and
are chosen at random, i.e. geographical vicinity is neglected. They can play
two possible strategies: cooperate (C) or defect (D). The players measure their
success by comparing their utilities with an estimate for the expected benefits
and update their strategy following a simple rule. Two versions of the model
are studied: 1) the deterministic version (the agents are either in definite
states C or D) and 2) the stochastic version (the agents have a probability c
of playing C). Using a general Master Equation we compute the equilibrium
states into which the system self-organizes, characterized by their average
probability of cooperation c_{eq}. Depending on the payoff matrix, we show that
c_{eq} can take five different values. We also consider the mixing of agents
using two different payoff matrices an show that any value of c_{eq} can be
reached by tunning the proportions of agents using each payoff matrix. In
particular, this can be used as a way to simulate the effect a fraction d of
"antisocial" individuals -incapable of realizing any value to cooperation- on
the cooperative regime hold by a population of neutral or "normal" agents.


title: A Matrix Kato-Bloch Perturbation Method for Hamiltonian Systems

abstract:
  A generalized version of the Kato-Bloch perturbation expansion is presented.
It consists of replacing simple numbers appearing in the perturbative series by
matrices. This leads to the fact that the dependence of the eigenvalues of the
perturbed system on the strength of the perturbation is not necessarily
polynomial. The efficiency of the matrix expansion is illustrated in three
cases: the Mathieu equation, the anharmonic oscillator and weakly coupled
Heisenberg chains. It is shown that the matrix expansion converges for a
suitably chosen subspace and, for weakly coupled Heisenberg chains, it can lead
to an ordered state starting from a disordered single chain. This test is
usually failed by conventional perturbative approaches.


title: String Theory, Universal Mind, and the Paranormal

abstract:
  A model consistent with string theory is proposed for so-called paranormal
phenomena such as extra-sensory perception (ESP). Our mathematical skills are
assumed to derive from a special 'mental vacuum state', whose origin is
explained on the basis of anthropic and biological arguments, taking into
account the need for the informational processes associated with such a state
to be of a life-supporting character. ESP is then explained in terms of shared
'thought bubbles' generated by the participants out of the mental vacuum state.
The paper concludes with a critique of arguments sometimes made claiming to
'rule out' the possible existence of paranormal phenomena.


title: Angula distanco en kaloto

abstract:
  A cap in a 2-D sphere is considered, smaller than an hemisphere. Two points
are randomly chosen in the cap. The probability density that the angular
separation between the points have a given value is obtained. The knowledge of
this function is important for some methods for determining the shape of the
universe.
  -----
  Kaloto de 2-D sfera estas studata, pli malgranda ol duonsfero. Du punktoj
estas hazarde elektataj en la kaloto. La probabla denso de angula distanco
inter la punktoj estas havita. Scio de tiu funkcio estas grava por kelkaj
metodoj por specifi la formo de l'universo.


title: An Unbinned Goodness-of-Fit Test Based on the Random Walk

abstract:
  We describe a test statistic for unbinned goodness-of-fit of data in one
dimension. The statistic is based on the two-dimensional Random Walk. The
rejection power of this test is explored both for simple and compound
hypotheses and, for the examples explored, it is found to be comparable to that
for the chisquare test. We discuss briefly how it may be possible to extend
this test to multi-dimensional data.


title:
Research on the Software of Track Reconstruction in Vertex Chamber of
  BESII

abstract:
  The software of track reconstruction of the vertex chamber of BESII-VCJULI
was studied when it was transplanted from the HP-Unix platform to PC-Linux. The
problems of distinct dictionary storage and precision treatment in these two
different platforms were found and settled in the modified software. Then the
obvious differences of the candidate track number in an event and some track
parameters caused by them were reduced from 74% to 0.02% and from 5% to 0.5%,
respectively. As a result, the quality of the track finding was greatly
improved and the CPU time saved.


title: Point-Contact Spectroscopy

abstract:
  The history is described of how one of the most commonly used electric
circuit components, an ordinary electric contact, has become a powerful tool
for the physicists to study various mechanisms of electron scattering in
metals. The physical principles of spectroscopy of quasi-particle excitations
in metals by means of point contacts (PCs) whose dimensions range from only a
few to tens of nanometers are presented in a popular form.


title:
Development of a multi-pixel photon sensor with single-photon
  sensitivity

abstract:
  A multi-pixel photon sensor with single-photon sensitivity has been
developed, based on a technology of a hybrid photo-detector (HPD) consisting of
a photocathode and a multi-pixel avalanche diode (MP-AD). The developed HPD has
a proximity focused structure, where a photocathode and an MP-AD are facing
each other with a small gap of 2.5 mm. The MP-AD, which has an effective area
of 16x16 mm2 composed of 8x8 pixels, has been specially designed for the HPD.
The gain of the HPD reaches 5x10^4, sufficiently high to detect single photons
with a timing resolution better than 100 ps. Number of photoelectrons up to
four can be clearly identified in a pulse-height spectrum as distinct peaks,
thanks to the low noise characteristics of the HPD. It is also demonstrated
that the HPD can be operated with good performance in a magnetic field as high
as 1.5 T


title:
Comment on 'Intense picosecond x-ray pulses from laser plasmas by use of
  nanostructured velvet targets'

abstract: Comment on the PRL paper.


title:
GePEToS : A Geant4 Monte Carlo simulation package for Positron Emission
  Tomography

abstract:
  GePEToS is a simulation framework developed over the last few years for
assessing the instrumental performance of future PET scanners. It is based on
Geant4, written in Object-Oriented C++ and runs on Linux platforms. The
validity of GePEToS has been tested on the well-known Siemens ECAT EXACT HR+
camera. The results of two application examples are presented : the design
optimization of a liquid Xe micro-PET camera dedicated to small animal imaging
as well as the evaluation of the effect of a strong axial magnetic field on the
image resolution of a Concorde P4 micro-PET camera.


title:
Deviations of the distributions of seismic energies from the
  Gutenberg-Richter law

abstract:
  A new non-parametric statistic is introduced for the characterization of
deviations from power laws. It is tested on the distribution of seismic
energies given by the Gutenberg-Richter law. Based on the two first statistical
log-moments, it evaluates quantitatively the deviations of the distribution of
scalar seismic moments from a power-like (Pareto) law. This statistic is close
to zero for the Pareto law with arbitrary power index, and deviates from zero
for any non-Pareto distribution. A version of this statistic for discrete
distribution of quantified magnitudes is also given. A methodology based on
this statistics consisting in scanning the lower threshold for earthquake
energies provides an explicit visualization of deviations from the Pareto law,
surpassing in sensitivity the standard Hill estimator or other known
techniques. This new statistical technique has been applied to shallow
earthquakes (h < 70 km) both in subduction zones and in mid-ocean ridge zones
(using the Harvard catalog of seismic moments, 1977-2000), and to several
regional catalogs of magnitudes (California, Japan, Italy, Greece). We discover
evidence for log-periodicity and thus for a discrete hierarchy of scales for
low-angle dipping, low-strain subduction zones with a preferred scaling ratio
g=7+-1 for seismic moments, compatible with a preferred scaling ratio of 2 for
linear rupture sizes, and consistent with previous reports. We propose a
possible mechanism in terms of cascades of fault competitions.


title: Time-domain simulation of the full hydrodynamic model

abstract:
  A simple upwind discretization of the highly coupled non-linear differential
equations which define the hydrodynamic model for semiconductors is given in
full detail. The hydrodynamic model is able to describe inertia effects which
play an increasing role in different fields of opto- and microelectronics. A
silicon $n^+ - n - n^+$ - structure is simulated, using the energy-balance
model and the full hydrodynamic model. Results for stationary cases are then
compared, and it is pointed out where the energy-balance model, which is
implemented in most of today's commercial semiconductor device simulators,
fails to describe accurately the electron dynamics. Additionally, a GaAs $n^+ -
n - n^+$-structure is simulated in time-domain in order to illustrate the
importance of inertia effects at high frequencies in modern submicron devices.


title: A Neutrino Horn Based on a Solenoid Lens

abstract:
  A neutrino horn based on a solenoid lens offers several potential advantages
over a conventionl toroidal horn when used with a multimegawatt proton source
to pursue studies of CP violation in neutrino oscillations. 1) A solenoid horn
can produce a neutrino spectrum with a sequence of peaks at momenta P = P_0 /
(2 n + 1), which has the same form as the sequence of momenta at which the
neutrino oscillation probability is maximal for a fixed distance from source to
detector. 2) The neutrino flux is a roughly equal mixture of neutrinos and
antineutrinos. 3) Rates of electron neutrinos from muon decay are suppressed
relative to those in a broad-band neutrino beam. 4) A solenoid magnet has its
coils far from the axis where the target is located, and hence the coils are
more readily protected from radiation damage. 5) A solenoid magnet is readily
compatible with a liquid metal target, as will be needed for use with very
intense proton sources. 6) A solenoid magnet is a DC device, and hence not
subject to pulse fatigue as for a conventional toroidal horn.


title: Isotropic Radiators

abstract:
  We give two examples of antennas with isotropic radiation patterns. Because
these involve elliptically polarized radiation, they evade the "hairy-ball
theorem" that suggests isotropic radiation would be impossible.


title: Gaussian Laser Beams via Oblate Spheroidal Waves

abstract:
  We deduce a set of circularly polarized Gaussian laser beam modes via a
separation-of-variables solution to the Helmholtz wave equation in oblate
spheriodal coordinates. On transforming to cylindrical coordinates these become
the well-known Gaussian-Laguerre modes.


title: An Electrostatic Wave

abstract:
  In general, Maxwell's equations require that a wave of electric field be
accompanied by a wave of magnetic field, and vice versa. However, it is
possible to have a plane wave in a dielectric medium with electric field E
parallel to the wave vector k (a longitudinal wave) with no time-dependent
magnetic field provided the electric displacement D is zero. We give an example
from plasma physics: the so-called Bernstein wave.


title: Magnetostatic Spin Waves

abstract:
  In general, Maxwell's equations require that a wave of magnetic field be
accompanied by a wave of electric field, and vice versa. In magnetic media it
is possible to have waves of magnetization with negligible electric field. We
discuss an example of this based on ferromagnetic spin waves.


title: Methods of Calculating Forces on Rigid Magnetic Media

abstract:
  Despite 180 years of theory on magnetism, it appears that the practice of
calculating forces on magnetic media is ambiguous, as illustrated by a recent
article by Casperson. Potentially troubling issues include: Which field B or H
should be used? Should the total field be used, or only the external field? And
if the latter, what is meant by "external"? Can/should effects of magnetization
currents and/or fictitious magnetic poles be included? What is the force on
only a portion of a circuit? We review several well-known approaches to
magnetic force calculations on elements of rigid circuits, and find it very
helpful to use an explicit example to compare and contrast the various methods.


title: Hidden Momentum in a Coaxial Cable

abstract:
  As an illustration of the concept of "hidden" mechanical momentum, we
consider a coaxial cable one end of which is connected to a battery and the
other to a load resistor. The nonzero electromagnetic momentum of this
configuration is balanced by the slight difference in the mechanical momenta of
the conduction electrons in the inner and outer conductors.


title: Maximal Gravity at the Surface of an Asteroid

abstract:
  The maximum strength of gravity at the surface of an object of a given mass
is not attained for a spherical shape, but for a small departure from
sphericity.


title: A Conducting Checkerboard

abstract:
  The problem of a conducting checkerboard has recently been solved via an
elliptic function whose argument is another elliptic function. The behavior of
the fields and currents near a vertex of the checkerboard pattern can be
discussed by more elementary methods.


title: A Capacitor Paradox

abstract:
  Consider two capacitors in parallel, but initially isolated by a switch such
that one is charged and the other not. After the switch is closed, the charges
redistribute themselves in such a way that the final electrostatic energy is
less than the initial. We show that the "missing" energy has been radiated away
by including an appropriate form of the radiation action in an equivalent
circuit analysis.


title: End-cap Modules for the ATLAS SCT

abstract:
  The performance of prototype end-cap modules of the ATLAS SemiConductor
Tracker (SCT) are discussed. The results are obtained in stand-alone as well as
test beam measurements performed on modules both before and after irradiation
with protons with a total dose corresponding to the expectation for ten years
of operation at the LHC. Finally, the present status of construction is
summarised.


title:
Properties of metastable alkaline-earth-metal atoms calculated using an
  accurate effective core potential

abstract:
  The first three electronically excited states in the alkaline-earth-metal
atoms magnesium, calcium, and strontium comprise the (nsnp) triplet P^o_J
(J=0,1,2) fine-structure manifold. All three states are metastable and are of
interest for optical atomic clocks as well as for cold-collision physics. An
efficient technique--based on a physically motivated potential that models the
presence of the ionic core--is employed to solve the Schroedinger equation for
the two-electron valence shell. In this way, radiative lifetimes, laser-induced
clock shifts, and long-range interaction parameters are calculated for
metastable Mg, Ca, and Sr.


title:
Predictability of Volcano Eruption: lessons from a basaltic effusive
  volcano

abstract:
  Volcano eruption forecast remains a challenging and controversial problem
despite the fact that data from volcano monitoring significantly increased in
quantity and quality during the last decades.This study uses pattern
recognition techniques to quantify the predictability of the 15 Piton de la
Fournaise (PdlF) eruptions in the 1988-2001 period using increase of the daily
seismicity rate as a precursor. Lead time of this prediction is a few days to
weeks. Using the daily seismicity rate, we formulate a simple prediction rule,
use it for retrospective prediction of the 15 eruptions,and test the prediction
quality with error diagrams. The best prediction performance corresponds to
averaging the daily seismicity rate over 5 days and issuing a prediction alarm
for 5 days. 65% of the eruptions are predicted for an alarm duration less than
20% of the time considered. Even though this result is concomitant of a large
number of false alarms, it is obtained with a crude counting of daily events
that are available from most volcano observatories


title:
Electromagnetic transitions of the helium atom in superstrong magnetic
  fields

abstract:
  We investigate the electromagnetic transition probabilities for the helium
atom embedded in a superstrong magnetic field taking into account the finite
nuclear mass. We address the regime \gamma=100-10000 a.u. studying several
excited states for each symmetry, i.e. for the magnetic quantum numbers
0,-1,-2,-3, positive and negative z parity and singlet and triplet symmetry.
The oscillator strengths as a function of the magnetic field, and in particular
the influence of the finite nuclear mass on the oscillator strengths are shown
and analyzed.


title: Non-linear space-time dynamics of ultrashort wave-packets in water

abstract:
  We have monitored the space-time transformation of 150-fs pulse, undergoing
self-focusing and filamentation in water, by means of the nonlinear gating
tech- nique. We have observed that pulse splitting and subsequent recombination
apply to axial temporal intensity only, whereas space-integrated pulse profile
preserves its original shape.


title: Frequency and Phase Noise in Non-Linear Microwave Oscillator Circuits

abstract:
  We have developed a new methodology and a time-domain software package for
the estimation of the oscillation frequency and the phase noise spectrum of
non-linear noisy microwave circuits based on the direct integration of the
system of stochastic differential equations representing the circuit. Our
theoretical evaluations can be used in order to make detailed comparisons with
the experimental measurements of phase noise spectra in selected oscillating
circuits.


title:
Large-scale grid-enabled lattice-Boltzmann simulations of complex fluid
  flow in porous media and under shear

abstract:
  Well designed lattice-Boltzmann codes exploit the essentially embarrassingly
parallel features of the algorithm and so can be run with considerable
efficiency on modern supercomputers. Such scalable codes permit us to simulate
the behaviour of increasingly large quantities of complex condensed matter
systems. In the present paper, we present some preliminary results on the large
scale three-dimensional lattice-Boltzmann simulation of binary immiscible fluid
flows through a porous medium derived from digitised x-ray microtomographic
data of Bentheimer sandstone, and from the study of the same fluids under
shear. Simulations on such scales can benefit considerably from the use of
computational steering and we describe our implementation of steering within
the lattice-Boltzmann code, called LB3D, making use of the RealityGrid steering
library. Our large scale simulations benefit from the new concept of capability
computing, designed to prioritise the execution of big jobs on major
supercomputing resources. The advent of persistent computational grids promises
to provide an optimal environment in which to deploy these mesoscale simulation
methods, which can exploit the distributed nature of compute, visualisation and
storage resources to reach scientific results rapidly; we discuss our work on
the grid-enablement of lattice-Boltzmann methods in this context.


title: The Vertex Tracker at Future e+e- Linear Colliders

abstract:
  The physics program of high energy e+e- linear colliders relies on the
accurate identification of fermions to study in details the profile of the
Higgs boson, search for new particles and later probe the multi-TeV mass region
by direct searches and precision electro-weak measurements. This paper reviews
the requirements, conceptual design and sensor R&D for the Vertex Tracker.


title: Exact nonparaxial beams of the scalar Helmholtz equation

abstract:
  It is shown that three-dimensional nonparaxial beams are described by the
oblate spheroidal exact solutions of the Helmholtz equation. For the first
time, their beam behaviour is investigated and their corresponding parameters
are defined. Using the fact that the beam width of the family of paraxial
Gaussian beams is described by an hyperbola, the connection between the
physical parameters of nonparaxial spheroidal beam solutions and those of
paraxial beams is formally stablished. These results are also helpful to
investigate the exact vector nonparaxial beams.