title:
Bidirectional propagation of cold atoms in a "stadium" shaped magnetic
  guide

abstract:
  We demonstrate the bi-directional propagation of more than 10 7 atoms (87 Rb)
around a "stadium" shaped magnetic ring that encloses an area of 10.9 cm 2,
with a flux density exceeding 10 11 atoms sec -1 cm -2 . Atoms are loaded into
the guide from a 2D + MOT at one side of the "stadium". An optical standing
wave pulse is applied to increase the propagation velocity of atoms along the
waveguide. The atom sample fills the entire ring in 200 ms when
counterpropagating atom sections of the original atom cloud recombine at their
initial positions after a full revolution. We discuss a possible extension of
this result to a guided atom ring interferometer.


title: Panic induced symmetry breaking in escaping ants

abstract:
  We report the phenomenon of symmetry breaking in ants escaping under panic.
Ants confined into a cell with two symmetrically located exits use both exits
in approximately equal proportions to abandon the cell in normal conditions,
but prefer one of the exits if panic is created by adding a repellent fluid.
This finding is consistent with the predictions of recent theoretical models
for the escape of humans in panic conditions, indicating that some features of
the collective behaviour of humans and ants can be similar when escaping under
panic.


title: Positronium-Atom Collisions

abstract:
  New results are presented for Ps(1s) scattering by H(1s), He(1$^1$S) and
Li(2s). Calculations have been performed in a coupled state framework, usually
employing pseudostates, and allowing for excitation of both the Ps and the
atom. In the Ps(1s)-H(1s) calculations the H$^-$ formation channel has also
been included using a highly accurate H$^-$ wave function. Resonances resulting
from unstable states in which the positron orbits H$^-$ have been calculated
and analysed. The new Ps(1s)-He(1$^1$S) calculations still fail to resolve
existing discrepancies between theory and experiment at very low energies. The
possible importance of the Ps$^-$ formation channel in all three collision
systems is discussed.


title: Prospects for P11B Fusion with the Dense Plasma Focus: New Results

abstract:
  Fusion with p11B has many advantages, including the almost complete lack of
radioactivity and the possibility of direct conversion of charged particle
energy to electricity, without expensive steam turbines and generators. But two
major challenges must be overcome to achieve this goal: obtaining average ion
energies well above 100keV and minimizing losses by bremsstrahlung x-rays.
Recent experimental and theoretical work indicates that these challenges may be
overcome with the dense plasma focus. DPF experiments at Texas A&M University
have demonstrated ion and electron average energies above 100keV in
several-micron-sized hot-spots or plasmoids. These had
density-confinement-time-energy products as high as 5.0 x10^15 keVsec/cm^3. In
these experiments we clearly distinguished between x-rays coming from the
hot-spots and the harder radiation coming from electron beam collisions with
the anode. In addition, new theoretical work shows that extremely high magnetic
fields, which appear achievable in DPF plasmoids, will strongly reduce
collisional energy transfer from ions to electrons. This reduction has been
studied in the context of neutron stars and occurs when ion velocities are too
small to efficiently excite electron transitions between Landau levels. It
becomes a major effect for fields above 5 gigagauss. This effect will allow
average electron energies to stay far below average ion energies and will thus
reduce x-ray cooling of p11B. In this case, fusion power will very
significantly exceed x-ray emitted power. While fields of only 0.4 gigagauss
have so far been demonstrated with the DPF, scaling laws indicate that much
higher fields can be reached.


title:
A general expression for bimolecular association rates with
  orientational constraints

abstract:
  We present a general expression for the association rate for partially
diffusion-controlled reactions between spherical molecules with an asymmetric
reactive patch on each surface. Reaction can occur only if the two patches are
in contact and properly aligned to within specified angular tolerances. This
extends and generalizes previous approaches that considered only axially
symmetric patches; the earlier solutions are shown to be limiting cases of our
general expression. Previous numerical results on the rate of protein-protein
association with high steric specificity are in very good agreement with the
value computed from our analytic expression. Using the new expression, we
investigate the influence of orientational constraints on the rate constant. We
find that for angular constraints of ~5-15 degrees, a typical range for example
in the case of protein-protein interactions, the reaction rate is about 2 to 3
orders of magnitude higher than expected from a simple geometric model.


title: Beyond Space And Time

abstract:
  The secret network of the universe: How quantum geometry might complete
Einstein's dream. - An informal introduction to quantum geometry (loop quantum
gravity), spin networks, quantum black holes, and the work of Abhay Ashtekar,
Carlo Rovelli, Lee Smolin and others.


title: High Luminosity Issues for DAPhNE Upgrade

abstract:
  We give an overview of presentations and discussions during the Accelerator
Working Group Session dedicated to High Luminosity Issues for a future upgrade
of the Frascati e+e- Phi-Factory DAPhNE at the Workshop "e+e- in the 1-2 GeV
range: Physics and Accelerator Prospects" held at Alghero (Italy) on 10-13
September 2003.


title:
MRI of the lung using hyperpolarized He-3 at very low magnetic field (3
  mT)

abstract:
  Optical pumping of He-3 produces large (hyper) nuclear-spin polarizations
independent of the magnetic resonance imaging (MRI) field strength. This allows
lung MRI to be performed at reduced fields with many associated benefits, such
as lower tissue susceptibility gradients and decreased power absorption rates.
Here we present results of 2D imaging as well as accurate 1D gas diffusion
mapping of the human lung using He-3 at very low field (3 mT). Furthermore,
measurements of transverse relaxation in zero applied gradient are shown to
accurately track pulmonary oxygen partial pressure, opening the way for novel
imaging sequences.


title:
In-situ acoustic-based analysis system for physical and chemical
  properties of the lower Martian atmosphere

abstract:
  The Environmental Acoustic Reconnaissance and Sounding experiment (EARS), is
composed of two parts: the Environmental Acoustic Reconnaissance (EAR)
instrument and the Environmental Acoustic Sounding Experiment (EASE). They are
distinct, but have the common objective of characterizing the acoustic
environment of Mars. The principal goal of the EAR instrument is "listening" to
Mars. This could be a most significant experiment if one thinks of everyday
life experience where hearing is possibly the most important sense after sight.
Not only will this contribute to opening up this important area of planetary
exploration, which has been essentially ignored up until now, but will also
bring the general public closer in contact with our most proximate planet. EASE
is directed at characterizing acoustic propagation parameters, specifically
sound velocity and absorption, and will provide information regarding important
physical and chemical parameters of the lower Martian atmosphere; in
particular, water vapor content, specific heat capacity, heat conductivity and
shear viscosity, which will provide specific constraints in determining its
composition. This would enable one to gain a deeper understanding of Mars and
its analogues on Earth. Furthermore, the knowledge of the physical and chemical
parameters of the Martian atmosphere, which influence its circulation, will
improve the comprehension of its climate now and in the past, so as to gain
insight on the possibility of the past presence of life on Mars. These aspect
are considered strategic in the contest of its exploration, as is clearly
indicated in NASA's four main objectives on "Long Term Mars Exploration
Program" (http://marsweb.jpl.nasa.gov/mer/science).


title:
Water bath calorimetric study of excess heat generation in 'resonant
  transfer' plasmas

abstract:
  Water bath calorimetry was used to demonstrate one more peculiar phenomenon
associated with a certain class of mixed gas plasmas termed resonant transfer,
or RT plasmas. Specifically, He/H2 (10%) (500 mTorr), Ar/H2 (10%) (500 mTorr),
and H2O(g) (500 and 200 mTorr) plasmas generated with an Evenson microwave
cavity consistently yielded on the order of 50% more heat than non RT plasma
(controls) such as He, Kr, Kr/H2 (10%), under identical conditions of gas flow,
pressure, and microwave operating conditions. The excess power density of RT
plasmas was of the order 10 W / cm-3. In earlier studies with these same RT
plasmas it was demonstrated that other unusual features were present including
dramatic broadening of the hydrogen Balmer series lines, unique vacuum
ultraviolet (VUV) lines, and in the case of water plasmas, population inversion
of the hydrogen excited states. Both the current results and the earlier
results are completely consistent with the existence of a hitherto unknown
exothermic chemical reaction, such as that predicted by Mills, occurring in RT
plasmas.


title:
A Measure of the Goodness of Fit in Unbinned Likelihood Fits; End of
  Bayesianism?

abstract:
  Maximum likelihood fits to data can be done using binned data (histograms)
and unbinned data. With binned data, one gets not only the fitted parameters
but also a measure of the goodness of fit. With unbinned data, currently, the
fitted parameters are obtained but no measure of goodness of fit is available.
This remains, to date, an unsolved problem in statistics. Using Bayes' theorem
and likelihood ratios, we provide a method by which both the fitted quantities
and a measure of the goodness of fit are obtained for unbinned likelihood fits,
as well as errors in the fitted quantities. The quantity, conventionally
interpreted as a Bayesian prior, is seen in this scheme to be a number not a
distribution, that is determined from data.


title: Improved surface treatment of the superconducting TESLA cavities

abstract:
  The proposed linear electron-positron collider TESLA is based on 1.3 GHz
superconducting niobium cavities for particle acceleration. For a
centre-of-mass energy of 500 GeV, an accelerating field of 23.4 MV/m is
required which is reliably achieved with a niobium surface preparation by
chemical etching. An upgrade of the collider to 800 GeV requires an improved
cavity preparation technique. In this paper, results are presented on
single-cell cavities which demonstrate that fields of up to 40 MV/m are
accessible by electrolytic polishing of the inner surface of the cavity.


title: Ozone Layer and the Formation of the Ozone Hole

abstract:
  The current state of this problem has briefly been considered. The hypothesis
on the formation of the ozone hole due to the action of some molecules emitted
by the rockets has been suggested.


title:
Terawatt-scale sub-10-fs laser technology - key to generation of
  GW-level attosecond pulses in X-ray free electron laser

abstract:
  We propose a technique for the production of attosecond X-ray pulses which is
based on the use of X-ray SASE FEL combined with a femtosecond laser system. A
few-cycle optical pulse from a Ti:sapphire laser interacts with the electron
beam in a two-period undulator resonant to 800 nm wavelength and produces
energy modulation within a slice of the electron bunch. Following the energy
modulator the electron beam enters the X-ray undulator and produces SASE
radiation. Due to energy modulation the frequency is correlated to the
longitudinal position within the few-cycle-driven slice of SASE radiation
pulse. The largest frequency offset corresponds to a single-spike pulse in the
time domain which is confined to one half-oscillation period near the central
peak electron energy. The selection of single-spike pulses is achieved by using
a crystal monochromator after the X-ray undulator. Our studies show that the
proposed technique is capable to produce 300 attoseconds long single pulses
with GW-level output power in the 0.1 nm wavelength range, and is applicable to
the European X-Ray Laser Project XFEL and the Linac Coherent Light Source at
SLAC.


title: Design formulas for short-wavelength FELs

abstract:
  Simple formulas for optimization of VUV and X-ray SASE FELs are presented.
The FEL gain length and the optimal beta-function are explicitly expressed in
terms of the electron beam and undulator parameters. The FEL saturation length
is estimated taking into account quantum diffusion in the undulator. Examples
of the FEL optimization are given. Parameters of a SASE FEL, operating at the
Compton wavelength, are suggested.


title: Controlled Hopf Bifurcation of a storage-ring free-electron laser

abstract:
  Local bifurcation control is a topic of fundamental importance in the field
of nonlinear dynamical systems. We discuss an original example within the
context of storage-ring free-electron laser physics by presenting a new model
that enables analytical insight into the system dynamics. The transition
between the stable and the unstable regimes, depending on the temporal
overlapping between the light stored in the optical cavity and the electrons
circulating into the ring, is found to be a Hopf bifurcation. A feedback
procedure is implemented and shown to provide an effective stabilization of the
unstable steady state.


title:
Evidences for Skeletal Structures in the Ocean from the Images Analyzed
  by Multilevel Dynamical Contrasting Method

abstract:
  An analysis of databases of photographic images of ocean's surface, taken
from various altitudes and for various types of rough ocean surface, revealed
the presence of an ocean's skeletal structures (OSS), which exhibit a tendency
toward self-similarity of structuring at various length scales (i.e., within
various "generations"). The topology of OSS appears to be identical to that of
skeletal structures (SS) which have been formerly found in a wide range of
length scales, media and for various phenomena. The typical OSS consists of
separate identical blocks which are linked together to form a network. Two
types of such blocks are found: (i) coaxial tubular (CT) structures with
internal radial bonds, and (ii) cartwheel-like (CW) structures, located either
on an axle or in the edge of CT block. The OSSs differ from the formerly found
SSs only by the fact that OSS, in their interior, are filled in with closely
packed OSSs of a smaller size (i.e. OSSs of former "generations"). We specially
discuss the phenomenon of skeletal blocks in the form of
vertically/horizontally oriented floating cylinders (VFC/HFC). The size of
these blocks is shown to grow with increasing rough water.


title:
Bandwidth comparison of photonic crystal fibers and conventional
  single-mode fibers

abstract:
  We experimentally compare the optical bandwidth of a conventional single-mode
fiber (SMF) with 3 different photonic crystal fibers (PCF) all optimized for
visible applications. The spectral attenuation, single-turn bend loss, and
mode-field diameters (MFD) are measured and the PCF is found to have a
significantly larger bandwidth than the SMF for an identical MFD. It is shown
how this advantage can be utilized for realizing a larger MFD for the PCF while
maintaining a bending resistant fiber.


title:
Achievement of 35 MV/m in the Superconducting Nine-Cell Cavities for
  TESLA

abstract:
  The Tera Electronvolt Superconducting Linear Accelerator TESLA is the only
linear electron-positron collider project based on superconductor technology
for particle acceleration. In the first stage with 500 GeV center-of-mass
energy an accelerating field of 23.4 MV/m is needed in the superconducting
niobium cavities which are operated at a temperature of 2 K and a quality
factor Q0 of 10 to the 10. This performance has been reliably achieved in the
cavities of the TESLA Test Facility (TTF) accelerator. The upgrade of TESLA to
800 GeV requires accelerating gradients of 35 MV/m. Using an improved cavity
treatment by electrolytic polishing it has been possible to raise the gradient
to 35 - 43 MV/m in single cell resonators. Here we report on the successful
transfer of the electropolishing technique to multi-cell cavities. Presently
four nine-cell cavities have achieved 35 MV/m, and a fifth cavity could be
excited to 39 MV/m. In two high-power tests it could be verified that
EP-cavities preserve their excellent performance after welding into the helium
cryostat and assembly of the high-power coupler. One cavity has been operated
for 1100 hours at the TESLA-800 gradient of 35 MV/m and 57 hours at 36 MV/m
without loss in performance.


title: Magnetic Backgrounds and Noncommutative Field Theory

abstract:
  This paper is a rudimentary introduction, geared at non-specialists, to how
noncommutative field theories arise in physics and their applications to string
theory, particle physics and condensed matter systems.

categories: physics.pop-ph cond-mat.mes-hall gr-qc hep-ph hep-th physics.gen-ph


title:
Volcanic forcing improves Atmosphere-Ocean Coupled General Circulation
  Model scaling performance

abstract:
  Recent Atmosphere-Ocean Coupled General Circulation Model (AOGCM) simulations
of the twentieth century climate, which account for anthropogenic and natural
forcings, make it possible to study the origin of long-term temperature
correlations found in the observed records. We study ensemble experiments
performed with the NCAR PCM for 10 different historical scenarios, including no
forcings, greenhouse gas, sulfate aerosol, ozone, solar, volcanic forcing and
various combinations, such as it natural, anthropogenic and all forcings. We
compare the scaling exponents characterizing the long-term correlations of the
observed and simulated model data for 16 representative land stations and 16
sites in the Atlantic Ocean for these scenarios. We find that inclusion of
volcanic forcing in the AOGCM considerably improves the PCM scaling behavior.
The scenarios containing volcanic forcing are able to reproduce quite well the
observed scaling exponents for the land with exponents around 0.65 independent
of the station distance from the ocean. For the Atlantic Ocean, scenarios with
the volcanic forcing slightly underestimate the observed persistence exhibiting
an average exponent 0.74 instead of 0.85 for reconstructed data.


title: The influence of complex material coverings on the bandwidth of antennas

abstract:
  The influence of material coverings on the antenna bandwidth is investigated
for antennas formed by thin electric or magnetic line sources. It is shown that
uniform thin layers of arbitrary passive materials (including Veselago,
left-handed, or double-negative materials) cannot help to overcome the
bandwidth limitations imposed by the amount of energy stored in the antenna
reactive field. Alternative possibilities offered by complex composite
materials in the antenna design are identified.


title:
Exact nonlinear analytic Vlasov-Maxwell tangential equilibria with
  arbitrary density and temperature profiles

abstract:
  The tangential layers are characterized by a bulk plasma velocity and a
magnetic field that are perpendicular to the gradient direction. They have been
extensively described in the frame of the Magneto-Hydro-Dynamic (MHD) theory.
But the MHD theory does not look inside the transition region if the transition
has a size of a few ion gyroradii. A series of kinetic tangential equilibria,
valid for a collisionless plasma is presented. These equilibria are exact
analytical solutions of the Maxwell-Vlasov equations. The particle distribution
functions are sums of an infinite number of elementary functions parametrized
by a vector potential. Examples of equilibria relevant to space plasmas are
shown. A model for the deep and sharp density depletions observed in the
auroral zone of the Earth is proposed. Tangential equilibria are also relevant
for the study of planetary environments and of remote astrophysical plasmas.


title: Average Angular Velocity

abstract:
  This paper addresses the problem of the separation of rotational and internal
motion. It introduces the concept of average angular velocity as the moment of
inertia weighted average of particle angular velocities. It extends and
elucidates the concept of Jellinek and Li (1989) of separation of the energy of
overall rotation in an arbitrary (non-linear) $N$-particle system. It
generalizes the so called Koenig's theorem on the two parts of the kinetic
energy (center of mass plus internal) to three parts: center of mass,
rotational, plus the remaining internal energy relative to an optimally
translating and rotating frame.


title: Computer Modeling of Edge Effects in Plasma Crystals

abstract:
  Dusty plasmas play an important role in astrophysical environments such as
protostellar clouds and ring systems. A computer simulation of such plasmas
will be presented.


title: Further Investigations of Dust Grain Orbital Behavior Around Neptune

abstract:
  Dust grain orbital behavior around Neptune is investigated using a fifth
order Runge-Jutta method.


title: Simulating Dust Lattice Waves in Plasma Crystals Using the Box_Tree Code

abstract: DAW and DLW modes within a dust crystal are examined using the Box_Tree code.


title: Dynamics of Interplanetary Planetismal Rings

abstract:
  Among the problems yet to be solved by current theories of solar system
formation is the origin of the Jupiter-family comets. Several possibilities are
examined using a fifth-order Runge-Kutta algorithm.


title: The Maxwell equations including magnetic monopoles

abstract:
  The derivation of the Maxwell equations is reproduced whereby magnetic
charges are included. This ansatz yields the results: 1) Longitudinal Ampere
forces in a differential magnetostatic force law are improbable. Otherwise an
electric current would generate magnetic charges. 2) Simple magnetic and
electric induced polarization phenomena are completely analogous and are
described by a Laplace equation. 3) Magnetic charges are the topological
defects of a magnetic spin field similar like electric charges are the
topological defects of an electric field. The magnetic charges should be
interconnected with an elastic or inertial field which compensates the torque
field generated by the magnetic moments of the anisotropic distributed spins.
4) Permanent magnetic fields can be understood to be caused by magnetic
charges. Consequently, a moving permanent magnet represents a magnetic current
which generates an electric field. 5) The electromagnetic tensors of energy and
momentum have some additional terms which are written down generally. 6)
Nonlinear electro-thermodynamic systems may violate the second law of
thermodynamics. This is illustrated by an electric cycle with a data storing
FET invented by Yusa & Sakaki.


title: Orbits of Dust Ejecta From Ceres

abstract:
  The question of whether asteroid ejecta can enter stable orbits about the
parent body is examined.


title: Matter and Light in Flatland

abstract:
  Using a non-material current through three new dimensions. It was possible to
build a particle-space model (a higher dimensional object intersecting a lower
dimensional world). The new dimensions solve the old problem of equal sign
walls huge electric repulsion force in the electric sphere model, since these
curved dimensions confine these walls, preventing them from coming apart. The
flat-fermion, which is a toroid, is resistant to be moved, intersects the space
(flatland) in two places at the same time (non-local) while moving, leaving a
sinusoidal electric field that uses the two dimensions of flatland and adopt a
toroidal intersection at rest, avoiding the information about its momentum. It
also has an anapole moment, which time consuming intersection in flatland
produces the flat-fermion magnetic dipole moment. The flat-fermion has an
enantiomer and both undergo a separation under an external magnetic field. On
the other hand, flat-photon, is also a toroid, is not resistant to be moved,
also intersects flatland in two places at the same time, but its sinusoidal
electric field uses one dimension less from the two available. Therefore, in
order to have mass the object should touch all the dimensions of flatland. Pure
quantum phenomena such as Self-Interference, the number of turns before being
identical and the uncertainty principle, as well as, fermion geometric
properties and its magnetic dipole moment are explained and derived.


title: Protoplanetary Migration and Creation of Scattered Planetismal Disks

abstract:
  The relationship between protoplanet migration and the formation of the
Kuiper Belt (planetesimal disk scattering) is examined.


title: Negative Momentum Compaction at KEKB

abstract:
  KEKB is a high luminosity e+e- collider for studying B mesons and has
achieved the design luminosity of 1034cm-2s-1 in 2003. In order to get higher
luminosity, we tested negative momentum compaction optics in the summer of
2003. We measured the bunch length using three methods at 0.7mA to 1.17mA bunch
current and confirmed the length was shortened with the negative momentum
compaction optics.


title: Photonic crystal fiber with a hybrid honeycomb cladding

abstract:
  We consider an air-silica honeycomb lattice and demonstrate a new approach to
the formation of a core defect. Typically, a high or low-index core is formed
by adding a high-index region or an additional air-hole (or other low-index
material) to the lattice, but here we discuss how a core defect can be formed
by manipulating the cladding region rather than the core region itself.
Germanium-doping of the honeycomb lattice has recently been suggested for the
formation of a photonic band-gap guiding silica-core and here we experimentally
demonstrate how an index-guiding silica-core can be formed by fluorine-doping
of the honeycomb lattice.


title: Recombination of low energy electrons with U$^{28+}$

abstract:
  We performed an extensive study of configuration mixing between the doubly
excited (doorway) states and complex multiply excited states of U$^{28+}$ near
its ionization threshold. The detailed investigation of complex spectrum and
analysis of the statistics of eigenstate components show that the dielectronic
(doorway) states weakly mixed with each other. However, they show substantial
mixing with the complex multiply excited states. This situation explains the
mechanism of low energy electron recombination with U$^{28+}$. We calculated
the energy averaged capture cross sections as a sum over dielectronic doorway
states and found our present calculation interprets well the experimental
recombination rates in the energy range of 1 to 100 eV.


title:
The role of inner-shell excitations in electron recombination with
  multiply charged complex ions

abstract:
  We performed an overview of the inner shell excitation phenomena in the study
of electron recombination with multiply charged complex ions such as Au$^{q+}$
(q=49-52) and Pb$^{53+}$. It is found the the inner shell excitations play a
significant role in the low energy electron recombination. Taking into account
these inner shell excitations we have calculated the energy avaraged capture
cross sections. The dielectronic rate coefficients are found to be in good
agreement with the experiment. We show that the contribution from the
inner-shell enhances the recombinmation rate by an order of magitude. We also
made an attempt to identify the resonaces observed by the experiment in
Au$^{50+}$ and Pb$^{53+}$. A prediction is made for the rate enhancement in
Au$^{52+}$ in which we found the configuration mixing between the doubly and
the complex multiply excited states. Analyzing the statistics of eigenstate
components we estimated the spreading width is about 0.85 a.u. which defines
the energy range within which strong mixing takes place.


title: An analytical analysis of vesicle tumbling under a shear flow

abstract:
  Vesicles under a shear flow exhibit a tank-treading motion of their membrane,
while their long axis points with an angle < 45 degrees with respect to the
shear stress if the viscosity contrast between the interior and the exterior is
not large enough. Above a certain viscosity contrast, the vesicle undergoes a
tumbling bifurcation, a bifurcation which is known for red blood cells. We have
recently presented the full numerical analysis of this transition. In this
paper, we introduce an analytical model that has the advantage of being both
simple enough and capturing the essential features found numerically. The model
is based on general considerations and does not resort to the explicit
computation of the full hydrodynamic field inside and outside the vesicle.


title:
Gravitational Interactions Between Protoplanets and Planetismal Disks of
  Equal Mass

abstract:
  Numerical simulations show that planetesimal systems with unevenly
distributed masses may actually be more stable than those where all the bodies
are of roughly equal size.


title: Impact Studies Using a One Stage Light Gas Gun

abstract:
  The Center for Astrophysics,Space Physics, and Engineering Research (CASPER)
has completed construction and calibration of a Light Gas Gun (LGG), which is
used for low velocity impact studies. At geosynchronous orbit, space debris can
impact commercial satellites at velocities of 500 m/s [1] reducing their useful
lifetime. Additionally, there is an ever-increasing population of abandoned
nonoperational satellites and related debris in these orbits [2]. Therefore, it
is important to clearly understand the physics behind how such collisions can
cause structural damage. This is most easily determined by measuring the damage
incurred on representative material exposed to test collisions in the
laboratory. Data collected in this manner will not only help illuminate the
shock physics involved but can also aid in providing methods for designing
advanced shielding for satellites.


title: Three Dimensional Annihilation Imaging of Antiprotons in a Penning Trap

abstract:
  We demonstrate three-dimensional annihilation imaging of antiprotons trapped
in a Penning trap. Exploiting unusual feature of antiparticles, we investigate
a previously unexplored regime in particle transport; the proximity of the trap
wall. Particle loss on the wall, the final step of radial transport, is
observed to be highly non-uniform, both radially and azimuthally. These
observations have considerable implications for the production and detection of
antihydrogen atoms.

categories: physics.plasm-ph hep-ex nucl-ex physics.gen-ph


title:
Feasibility of a magnetic suspension for second generation Gravitational
  Wave interferometers

abstract:
  This paper deals with the use of a magnetic levitation system as a part of a
multi-stage seismic attenuator for gravitational wave interferometric antennas.
The proposed configuration uses permanent magnets in attraction to balance the
suspended weight, plus a closed loop position control to obtain a stable
levitation. The system is analyzed using a MATLAB simulation code to compute
the forces exerted by extended magnets. The validity of this model has been
tested by a comparison with the experimental data from a levitated suspension
prototype.


title:
Quantum Field Mechanics: Complex-Dynamical Completion of Fundamental
  Physics and Its Experimental Implications

abstract:
  This report provides a brief review of recently developed extended framework
for fundamental physics, designated as Quantum Field Mechanics and including
causally complete and intrinsically unified theory of explicitly emerging
elementary particles, their inherent properties, quantum and relativistic
behaviour, interactions and their results. Essential progress with respect to
usual theory is attained due to the unreduced, nonperturbative analysis of
arbitrary interaction process revealing a qualitatively new phenomenon of
dynamic multivaluedness of interaction results and their dynamically entangled
structure giving rise to universally defined dynamic complexity
(physics/9806002) and absent in usual, always perturbative and dynamically
single-valued models with the zero value of unreduced complexity (including
substitutes used for "complexity", "chaoticity", "self-organisation", etc.). It
is shown how the observed world structure, starting from elementary particles
and their interactions, dynamically emerges from the unreduced interaction
between two initially homogeneous, physically real protofields
(quant-ph/9902015, quant-ph/9902016). In that way one avoids arbitrary
imposition of abstract entities and unprovable postulates or "principles", let
alone "mysteries", of conventional theory, which now obtain unified, consistent
and realistic explanation in terms of unreduced dynamic complexity. We complete
the description of fundamental world structure emergence and properties by an
outline of experimental implications and resulting causally substantiated
change of research strategy.


title:
Absolute frequency measurements of the $D_2$ line and fine-structure
  interval in $^{39}$K

abstract:
  We report a value for the $D_2$-line frequency of $^{39}$K with 0.25 ppb
uncertainty. The frequency is measured using an evacuated ring-cavity resonator
whose length is calibrated against a reference laser. The $D_2$ line presents a
problem in identifying the line center because the closely-spaced energy levels
of the excited state are not resolved. We use computer modelling of the
measured spectrum to extract the line center and obtain a value of 391 015
578.040(75) MHz. In conjunction with our previous measurement of the $D_1$
line, we determine the fine-structure interval in the $4P$ state to be 1 729
997.132(90) MHz. The results represent significant improvement over previous
values.


title: The Signal Space Separation method

abstract:
  Multichannel measurement with hundreds of channels essentially covers all
measurable degrees of freedom of a curl and source free vector field, like the
magnetic field in a volume free of current sources (e.g. in
magnetoencephalography, MEG). A functional expansion solution of Laplace's
equation enables one to separate signals arising from the sphere enclosing the
interesting sources, e.g. the currents in the brain, from the rest of the
signals. The signal space separation (SSS) is accomplished by calculating
individual basis vectors for each term of the functional expansion solution to
create a signal basis covering all measurable signal vectors. Any signal vector
has a unique SSS decomposition with separate coefficients for the interesting
signals and signals coming from outside the interesting volume. Thus, SSS basis
provides an elegant method to remove external disturbances, and to transform
the interesting signals to virtual sensor configurations. SSS can also be used
in compensating the movements of the subject and removing the artefacts caused
by magnetized particles in the subject.


title: Virtual model of the differential pulse reversible calorimeter

abstract:
  A new method of absolute heat capacity measurement was developed in the
Department of Biological Systems Physics at the E. Andronikashvili Institute of
Physics, Georgian Academy of Sciences. This is the method of absolute heat
capacity measurement of the differential calorimetric ampoule sample and
reference cells and the adiabatic shell temperature difference registration
while stepwise alteration of temperature (increase or decrease) of system
occurs. The new method makes possible to determine both the heat capacities of
the sample and reference cells and their difference. The method of cell
temperature difference compensation is used in order to decrease in the time of
equilibrium establishment. The proposed method of absolute heat capacity
measurement was implemented in the model of the virtual differential pulse
reversible calorimeter.


title:
Counterposed phase velocity and energy-transport velocity vectors in a
  dielectric-magnetic uniaxial medium

abstract:
  When a plane wave is launched from a plane surface in a linear, homogenous,
dielectric-magnetic, uniaxial medium, we show that its phase velocity and the
energy-transport velocity vectors can be counterposed (i.e., lie on different
sides of the surface normal) under certain circumstances.


title:
Structural, Vibrational and Mechanical Studies of Hydroxyapatite
  produced by wet-chemical methods

abstract:
  Hydroxyapatite samples were produced by two different wet-chemical methods,
and characterized by x-ray diffraction, infrared and compression strength
measurements. The x-ray diffraction measurements were simulated using the
Rietveld method, and structural data as lattice parameters and average
crystallite size were obtained. The infrared spectra showed the presence of
CO$_3^{2-}$ ions in all samples, indicating a contamination by these ions. By
mixing samples produced by both methods, a bioceramic was obtained and, after
sintering, samples with very high compression strengths (26--30 MPa) were
obtained.


title:
Bernoulli process with 282 ky periodicity is detected in the R-N
  reversals of the earth's magnetic field

abstract:
  Investigating the polarity time scales for the last 118 My a Bernoulli
process with p=0.5 overriding with a Gaussian noise have been detected for the
R-N magnetic reversals. The Bernoulli trials are separated by 282 ky. The
frequency of the Bernoulli process correlates to planetary cycles and
consistent with an impact triggered global cooling mechanism. The detected
pattern allows calculating the probability of an upcoming R-N reversal between
any time intervals.


title: Green's function for rf-driven current in a toroidal plasma

abstract:
  The Green's function for rf-driven currents in a toroidal plasma is
calculated in the long mean-free-path limit.


title: Momentum transfer to small particles by aloof electron beams

abstract:
  The force exerted on nanoparticles and atomic clusters by fast passing
electrons like those employed in transmission electron microscopes are
calculated and integrated over time to yield the momentum transferred from the
electrons to the particles. Numerical results are offered for metallic and
dielectric particles of different sizes (0-500 nm in diameter) as well as for
carbon nanoclusters. Results for both linear and angular momentum transfers are
presented. For the electron beam currents commonly employed in electron
microscopes, the time-averaged forces are shown to be comparable in magnitude
to laser-induced forces in optical tweezers. This opens up the possibility to
study optically-trapped particles inside transmission electron microscopes.


title: Agglomeration of Oppositely Charged Particles in Nonpolar Liquids

abstract:
  We study the aggregation of insulating electrically charged spheres suspended
in a nonpolar liquid. Regarding the van der Waals interaction as an
irreversible sticking force, we are especially interested in the charge
distribution after aggregation. Solving the special case of two oppositely
charged particles exactly, it is shown that the surface charges either
recombine or form a residual dipole, depending on the initial condition. The
theoretical findings are compared with numerical results from Monte Carlo
simulations.


title: Discrete Space Time and Dark Energy

abstract:
  In recent times, Discrete Space Time Architectures are being considered, in
the context of Quantum Gravity, Quantum Super Strings, Dark Energy and so on.
We show that such a scheme is intimately tied up with a varying $G$ cosmology,
which again explains otherwise inexplicable observations like the anomalous
accelerations of Pioneer space crafts as also considerations involving the Zero
Point Field, Random Electrodynamics and the derivation of Quantum Mechanical
effects therefrom as also intertial mass.


title:
Modeling the Effects of Velocity, Spin, Frictional Coefficient, and
  Impact Angle on Deflection Angle in Near-elastic Collisions of Phenolic Resin
  Spheres

abstract:
  A simple model is outlined to describe the collision of cast
phenol-formaldehyde resin spheres such as the balls used in the parlor game of
pocket billiards, based in part on the famous analysis of elastic collisions
developed by Heinrich Hertz over 100 years ago. The analysis treats the normal
and tangential components of the initial sphere's velocity independently as it
collides with a stationary identical second sphere. The collective effects of
these and other parameters on the trajectory of the second sphere are provided
in the conclusions.


title: The CMS Si-strip Tracker

abstract:
  The Compact Muon Solenoid (CMS) experiment at LHC features the largest
Silicon Strip Tracker (SST) ever build. This device is immersed in a 4T
magnetic field and, in conjunction with a Pixel system, it allows the momentum
of the charged particles to be measured and the heavy-flavour final states to
be tagged despite the hostile radiation environment. The impact of operating
conditions and physics requirements on the SST layout and design choices is
discussed and the expected performances are reviewed. The SST collaboration is
now facing the production of the ~15000 modules and their assembly into the SST
substructures. A status is given.


title: On the possibility of "correlation cooling" of ultracold neutral plasmas

abstract:
  Recent experiments with ultracold neutral plasmas show an intrinsic heating
effect based on the development of spatial correlations. We investigate whether
this effect can be reversed, so that imposing strong spatial correlations could
in fact lead to cooling of the ions. We find that cooling is indeed possible.
It requires, however, a very precise preparation of the initial state. Quantum
mechanical zero-point motion sets a lower limit for ion cooling.


title: Enhanced radiometric forces

abstract:
  Crookes' Radiometer exploits thermal forces arising from temperature
gradients in rarefied gases. This instrument has remained confined to
educational physics because of the very small size of the radiometric effect
and because of the necessity of an evacuated environment for operation. In this
article the physics of this instrument is reviewed, different theories are
compared and some general principles are derived. A method for enhancing the
radiometric effect and for generating radiometric forces at higher pressures is
proposed.


title:
The "0.4 eV" Shape Resonance of Electron Scattering from Mercury in a
  Franck-Hertz Tube

abstract:
  The alternative version of the Franck-Hertz experiment with mercury, in which
a two-grid tube is used as a combination of electron gun, equipotential
collision space, and detection cell, was analyzed recently in considerable
detail. In particular, it was inferred that, at optimal pressure, the formation
of peaks in the anode current at inelastic thresholds is mediated inside the
detection cell by the large variation, a maximum at 0.4 eV, in the cross
section for elastic scattering. This variation is due to a shape resonance in
the electron-mercury system and is observable persuasively at the onset of
anode current as a sharp peak followed by a clear minimum. In the present
paper, the passage of electrons through the second grid to anode region is
analyzed in terms of kinetic theory. The discussion is based on a simplified
expression for the electron current derivable from an approximate form of the
Boltzmann transport equation that maintains the spatial density gradient but
omits elastic energy losses. The estimated range of pressure underlying this
kind of idealization is in good agreement with experiment. An explicit solution
is obtained by constructing an analytic expression for the momentum transfer
cross section of mercury using a recent theory of generalized Fano profiles for
overlapping resonances. This solution is used in order to model successfully
the formation of peaks at the threshold of anode current and at excitation
potentials, and to explain the dependence of the observed profiles on the
pressure and on the sign and magnitude of the potential across the detection
cell.


title: Self-Similar Evolution of Parabolic Pulses in a Laser

abstract:
  Self-similar propagation of ultrashort, parabolic pulses in a laser resonator
is observed theoretically and experimentally. This constitutes a new type of
pulse-shaping in modelocked lasers: in contrast to the well-known static
(soliton-like) and breathing (dispersion-managed soliton) pulse evolutions,
asymptotic solutions to the nonlinear wave equation that governs pulse
propagation in most of the laser cavity are observed. Stable self-similar
pulses exist with energies much greater than can be tolerated in soliton-like
pulse shaping, and this will have implications for practical lasers.


title:
Modified geometrical optics of a smoothly inhomogeneous isotropic
  medium: the anisotropy, Berry phase, and the optical Magnus effect

abstract:
  In this paper we present a modification of the geometrical optics method,
which allows one to properly separate the complex amplitude and the phase of
the wave solution. Appling this modification to a smoothly inhomogeneous
isotropic medium, we show that in the first geometrical optics approximation
the medium is weakly anisotropic. The refractive index, being dependent on the
direction of the wave vector, contains the correction, which is proportional to
the Berry geometric phase. Two independent eigenmodes of right-hand and
left-hand circular polarizations exist in the medium. Their group velocities
and phase velocities differ. The difference in the group velocities results in
the shift of the rays of different polarizations (the optical Magnus effect).
The difference in the phase velocities causes the increase of Berry phase along
with the interference of two modes leading to the familiar Rytov law about the
rotation of the polarization plane of a wave. The theory developed suggests
that both the optical Magnus effect and the Berry phase are accompanying
nonlocal topological effects. In this paper the Hamilton ray equations giving a
unified description for both of these phenomena have been derived and also a
novel splitting effect for a ray of noncircular polarization has been
predicted. Specific examples are also discussed.


title: On the intermittency exponent of the turbulent energy cascade

abstract:
  We consider the turbulent energy dissipation from one-dimensional records in
experiments using air and gaseous helium at cryogenic temperatures, and obtain
the intermittency exponent via the two-point correlation function of the energy
dissipation. The air data are obtained in a number of flows in a wind tunnel
and the atmospheric boundary layer at a height of about 35 m above the ground.
The helium data correspond to the centerline of a jet exhausting into a
container. The air data on the intermittency exponent are consistent with each
other and with a trend that increases with the Taylor microscale Reynolds
number, R_\lambda, of up to about 1000 and saturates thereafter. On the other
hand, the helium data cluster around a constant value at nearly all R_\lambda,
this being about half of the asymptotic value for the air data. Some possible
explanation is offered for this anomaly.


title: Photoluminescence studies study of a phenyl-substituted PPV

abstract:
  We report on the photophysics of a phenyl-substituted PPV both in solution
and as a film. For both systems we have studied the decay of the
photoluminescence and of the emission anisotropy for a large set of wavelengths
spanning the entire photoluminescence spectrum. At long wavelengths the decay
behavior is that of an interchain species. At the shortest wavelengths the
decay of the photoluminescence from the film is observed to have a long-lived
component, in addition to the rapidly decaying component usually associated
with energy transfer. We attribute this slow component to emission by isolated
intrachain excitons with reduced nonradiative relaxation.


title: Measuring the gain dynamics in a conjugated polymer film

abstract:
  We present a simple method for measuring the gain decay time in a conjugated
polymer film by optically exciting the film with two mutually delayed
ultrashort pump pulses. When the pump is set at such a power level that
amplified spontaneous emission marginally develops along the polymer waveguide,
the total output emitted from its edge decays exponentially as a function of
the interpulse delay. The corresponding decay time represents the decay time of
the gain of the polymer material.


title: A limitation of the Bruggeman formalism for homogenization

abstract:
  The Bruggeman formalism provides an estimate of the effective permittivity of
a particulate composite medium comprising two component mediums. The Bruggeman
estimate is required to lie within the Wiener bounds and the Hashin-Shtrikman
bounds. Considering the homogenization of weakly dissipative component mediums
characterized by relative permittivities with real parts of opposite signs, we
show that the Bruggeman estimate may not be not physically reasonable when the
component mediums are weakly dissipative; furthermore, both the Wiener bounds
and the Hashin-Shtrikman bounds exhibit strong resonances.


title:
Enhanced transmission versus localization of a light pulse by a
  subwavelength metal slit: Can the pulse have both characteristics?

abstract:
  The existence of resonant enhanced transmission and collimation of light
waves by subwavelength slits in metal films [for example, see T.W. Ebbesen et
al., Nature (London) 391, 667 (1998) and H.J. Lezec et al., Science, 297, 820
(2002)] leads to the basic question: Can a light be enhanced and simultaneously
localized in space and time by a subwavelength slit? To address this question,
the spatial distribution of the energy flux of an ultrashort (femtosecond)
wave-packet diffracted by a subwavelength (nanometer-size) slit was analyzed by
using the conventional approach based on the Neerhoff and Mur solution of
Maxwell's equations. The results show that a light can be enhanced by orders of
magnitude and simultaneously localized in the near-field diffraction zone at
the nm- and fs-scales. Possible applications in nanophotonics are discussed.


title: An elliptic property of parabolic trajectories

abstract:
  The curve joining the points of maximum height in the parabolas of ideal
projectile motion is shown to be an ellipse. Some features of the motion are
illustrated with the help of such ellipse.


title: Optical microrheology using rotating laser-trapped particles

abstract:
  We demonstrate an optical system that can apply and accurately measure the
torque exerted by the trapping beam on a rotating birefringent probe particle.
This allows the viscosity and surface effects within liquid media to be
measured quantitatively on a micron-size scale using a trapped rotating
spherical probe particle. We use the system to measure the viscosity inside a
prototype cellular structure.


title:
Quantum mechanical constraints on the measurement of the density of the
  electromagnetic energy

abstract:
  It is considered constraints imposed by the quantum mechanics on the
measurement of the density of the electromagnetic energy. First, the energy of
the electromagnetic wave and the volume (time) are bound with the Heisenberg
uncertainty principle. It reduces from double to ordinary the relativistic
effect for the density of the electromagnetic energy. Second, the frequency of
photons and the number of photons are bound with the Heisenberg uncertainty
principle. Then relativistic effects for the frequency of photons and for the
number of photons are incompatible.


title: Bose-Einstein Condensate of Trimers Dressed by Atom-Dimer Cooper Pairs

abstract:
  We theoretically examine the neutral atom-molecule analogue of the anomalous
quantum correlations between degenerate electrons, i.e., Cooper pairs, that are
responsible for superconductivity. Based on rogue dissociation of triatomic
molecules (trimers) into opposite-momentum pairs of atoms and diatomic
molecules (dimers) via a photoassociation or Feshbach resonance, we find a
superfluid transition to a Bose-Einstein condensate of trimers dressed by
atom-dimer Cooper pairs, at a critical temperature in reach of present
ultracold technology.


title: Deriving relativistic momentum and energy

abstract:
  We present a new derivation of the expressions for momentum and energy of a
relativistic particle. In contrast to the procedures commonly adopted in
textbooks, the one suggested here requires only the knowledge of the
composition law for velocities along one spatial dimension, and does not make
use of the concept of relativistic mass, or of the formalism of four-vectors.
The basic ideas are very general and can be applied also to kinematics
different from the Newtonian and Einstein ones, in order to construct the
corresponding dynamics.


title:
Underlying mechanism of numerical instability in large eddy simulation
  of turbulent flows

abstract:
  This paper extends our recent theoretical work concerning the feasibility of
stable and accurate computation of turbulence using a large eddy simulation
[Ida and Taniguchi, Phys. Rev. E 68, 036705 (2003)]. In our previous paper, it
was shown, based on a simple assumption regarding the instantaneous streamwise
velocity, that the application of the Gaussian filter to the incompressible
Navier-Stokes equations can result in the appearance of a numerically unstable
term that can be decomposed into positive and negative viscosities. That result
raises the question as to whether an accurate solution can be achieved by a
numerically stable subgrid-scale model. In the present paper, based on
assumptions regarding the statistically averaged velocity, we present similar
theoretical investigations to show that in several situations, the shears
appearing in the statistically averaged velocity field numerically destabilize
the fluctuation components because of the derivation of a numerically unstable
term that represents negative diffusion in a fixed direction. This finding can
explain the problematic numerical instability that has been encountered in
large eddy simulations of wall-bounded flows. The present result suggests that
this numerical problem is universal in large eddy simulations, and that if
there is no failure in modeling, the resulting subgrid-scale model can still
have unstable characteristics; that is, the known instability problems of
several existing subgrid-scale models are not something that one may remove
simply by an artificial technique, but must be taken seriously so as to treat
them accurately.


title:
Improving probabilistic weather forecasts using seasonally varying
  calibration parameters

abstract:
  We show that probabilistic weather forecasts of site specific temperatures
can be dramatically improved by using seasonally varying rather than constant
calibration parameters.


title:
Singular vector ensemble forecasting systems and the prediction of flow
  dependent uncertainty

abstract:
  The ECMWF ensemble weather forecasts are generated by perturbing the initial
conditions of the forecast using a subset of the singular vectors of the
linearised propagator. Previous results show that when creating probabilistic
forecasts from this ensemble better forecasts are obtained if the mean of the
spread and the variability of the spread are calibrated separately. We show
results from a simple linear model that suggest that this may be a generic
property for all singular vector based ensemble forecasting systems based on
only a subset of the full set of singular vectors.


title: Atmospheric turbulence within and above an Amazon forest

abstract:
  In this paper, we discuss the impact of a rain forest canopy on the
statistical characteristics of atmospheric turbulence. This issue is of
particular interest for understanding on how the Amazon terrestrial biosphere
interact with the atmosphere. For this, we used a probability density function
model of velocity and temperature differences based on Tsallis' non-extensive
thermostatistics. We compared theoretical results with experimental data
measured in a 66 m micrometeorological tower, during the wet-season campaign of
the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA).
Particularly, we investigated how the value of the entropic parameter is
affected when one moves into the canopy, or when one passes from day/unstable
to night/stable conditions. We show that this new approach provides interesting
insights on turbulence in a complex environment such as the Amazon forest.


title: The locality hypothesis in density-functional theory: An exact theorem

abstract:
  The locality hypothesis in density-functional theory (DFT) states that the
functional derivative of the Hohenberg-Kohn universal functional can be
expressed as a local multiplicative potential function, and this is the basis
of DFT and of the successful Kohn-Sham model. Nesbet has in several papers
[Phys. Rev. A \bf{58}, R12 (1998); \it{ibid.} A \bf{65}, 010502 (2001); Adv.
Quant. Chem, \bf{43}, 1 (2003)] claimed that this hypothesis is in conflict
with fundamental quantum physics, and as a consequence that the Hohenberg-Kohn
theory cannot be generally valid. We have in a Comment to the Physical Review
[Phys. Rev. A \bf{67}, 056501 (2003)] commented upon these works and recently
extended the arguments [Adv. Quant. Chem. \bf{43}, 95 (2003)]. We have shown
that there is no such conflict and that the locality hypothesis is inherently
exact. In the present work we have furthermore verified this numerically by
constructing a local Kohn-Sham potential for the $1s2s ^3S$ state of helium
that generates the many-body electron density and shown that the corresponding
$2s$ Kohn-Sham orbital eigenvalue agrees with the ionization energy to nine
digits. Similar result is obtained with the Hartree-Fock density. In addition
to verifying the locality hypothesis, this confirms the theorem regarding the
Kohn-Sham eigenvalue of the highest occupied orbital.


title: PhysicsGP: A Genetic Programming Approach to Event Selection

abstract:
  We present a novel multivariate classification technique based on Genetic
Programming. The technique is distinct from Genetic Algorithms and offers
several advantages compared to Neural Networks and Support Vector Machines. The
technique optimizes a set of human-readable classifiers with respect to some
user-defined performance measure. We calculate the Vapnik-Chervonenkis
dimension of this class of learning machines and consider a practical example:
the search for the Standard Model Higgs Boson at the LHC. The resulting
classifier is very fast to evaluate, human-readable, and easily portable. The
software may be downloaded at: http://cern.ch/~cranmer/PhysicsGP.html


title:
Constant of Motion for several one-dimensional systems and outlining the
  problem associated with getting their Hamiltonians

abstract:
  The constants of motion of the following systems are deduced: a relativistic
particle with linear dissipation, a no-relativistic particle with a time
explicitly depending force, a no-relativistic particle with a constant force
and time depending mass, and a relativistic particle under a conservative force
with position depending mass. The problem of getting the Hamiltonian for these
systems is determined by getting the velocity as an explicit function of
position and generalized linear momentum, and this problem can be solved a
first approximation for the first above system.


title:
Classical aspects of ultracold atom wavepacket motion through
  microstructured waveguide bends

abstract:
  The properties of low-density, low-energy matter wavepackets propagating
through waveguide bends are investigated. Time-dependent quantum mechanical
calculations using simple harmonic oscillator confining potentials are
performed for a range of parameters close to those accessible by recent ``atom
chip''-based experiments. We compare classical calculations based on
Ehrenfest's theorem to these results to determine whether classical mechanics
can predict the amount of transverse excitation as measured by the transverse
heating. The present results thus elucidate some of the limits for which matter
wave propagation through microstructures can be reliably considered using
classical particle motion.


title:
Evidence of the production of hot hydrogen atoms in RF plasmas by
  catalytic reactions between hydrogen and oxygen species

abstract:
  Selective H-atom line broadening was found to be present throughout the
volume (13.5 cm ID x 38 cm length) of RF generated H2O plasmas in a GEC cell.
Notably, at low pressures (ca. <0.08 Torr), a significant fraction (ca. 20%) of
the atomic hydrogen was 'hot' with energies greater than 40 eV with a pressure
dependence, but only a weak power dependence. The degree of broadening was
virtually independent of the position studied within the GEC cell, similar to
the recent finding for He/H2 and Ar/H2 plasmas in the same GEC cell. In
contrast to the atomic hydrogen lines, no broadening was observed in oxygen
species lines at low pressures. Also, in control Xe/H2 plasmas run in the same
cell at similar pressures and adsorbed power, no significant broadening of
atomic hydrogen, Xe, or any other lines was observed. Stark broadening or
acceleration of charged species due to high electric fields can not explain the
results since (i) the electron density was insufficient by orders of magnitude,
(ii) the RF field was essentially confined to the cathode fall region in
contrast to the broadening that was independent of position, and (iii) only the
atomic hydrogen lines were broadened. Rather, all of the data is consistent
with a model that claims specific, predicted, species can act catalytically
through a resonant energy transfer mechanism to create hot hydrogen atoms in
plasmas.


title:
Coherent control and manifestation of inequality of forward and reversed
  processes in optics

abstract:
  The experiments with broadband down-converted light clearly show inequality
of forward and reversed processes in optics.

categories: physics.optics hep-ph physics.gen-ph quant-ph


title: Nonlinear model for magnetosonic shocklets in plasmas

abstract:
  Exact nonlinear equations for magnetosonic shocklets in a uniform hot
magnetoplasma are derived by using the nonlinear magnetohydrodynamic equations.
Analytic as well as numerical solutions of the nonlinear equations are
presented. Shock-like structures of the ion fluid velocity and magnetic field
(or the plasma density) perturbations are obtained. The results may have
relevance to the understanding of fast magnetosonic shocklets that have been
recently observed by onboard instruments of the Cluster spacecraft at the
Earth's bow shock.


title: The Hertz contact in chain elastic collisions

abstract:
  A theoretical analysis about the influence of the Hertz elastic contact on a
three body chain collision is presented. In spite of the elastic character of
the collision, the final velocity of each particle depends on the particular
interaction between them. A system involving two elastic spheres falling
together one in top of the other under the action of gravity, and colliding
with an horizontal hard wall is studied in detail. The effect of the Hertz
contact interaction can be easily put in evidence for some particular
situations.


title: Enhanced group velocity in metamaterials

abstract:
  The Bruggeman formalism is implemented to estimate the refractive index of an
isotropic, dielectric, homogenized composite medium (HCM). Invoking the
well--known Hashin--Shtrikman bounds, we demonstrate that the group velocity in
certain HCMs can exceed the group velocities in their component materials. Such
HCMs should therefore be considered as metamaterials.


title: Dialogue on the Principle of Mass-Energy Equivalence

abstract:
  This paper is directed to the readers who are familiar with the earlier
papers by the author on the topic of mass-energy equivalence. A number of
important questions about the total energy equation H=mv^2 and its implications
are answered qualitatively. The relationship between the equation H=mv^2 and
the 4-vector (Minkowski) representation of Special Relativity is discussed in
detail. Other issues, such as de Broglie's original formulation of wave
mechanics, are also discussed.


title:
Pattern Recognition and Event Reconstruction in Particle Physics
  Experiments

abstract:
  This report reviews methods of pattern recognition and event reconstruction
used in modern high energy physics experiments. After a brief introduction into
general concepts of particle detectors and statistical evaluation, different
approaches in global and local methods of track pattern recognition are
reviewed with their typical strengths and shortcomings. The emphasis is then
moved to methods which estimate the particle properties from the signals which
pattern recognition has associated. Finally, the global reconstruction of the
event is briefly addressed.


title: The Thermodynamic Arrow: Puzzles and Pseudo-puzzles

abstract:
  For more than a century, physics has known of a puzzling conflict between the
T-asymmetry of thermodynamic phenomena and the T-symmetry of the underlying
microphysics on which these phenomena depend. This paper provides a guide to
the current status of this puzzle, distinguishing the central issue from
various issues with which it may be confused. It is shown that there are two
competing conceptions of what is needed to resolve the puzzle of the
thermodynamic asymmetry, which differ with respect to the number of distinct
T-asymmetries they take to be manifest in the physical world. On the preferable
one-asymmetry conception, the remaining puzzle concerns the ordered
distribution of matter in the early universe. The puzzle of the thermodynamic
arrow thus becomes a puzzle for cosmology.


title: Electron Temperature of Ultracold Plasmas

abstract:
  We study the evolution of ultracold plasmas by measuring the electron
temperature. Shortly after plasma formation, competition between heating and
cooling mechanisms drives the electron temperature to a value within a narrow
range regardless of the initial energy imparted to the electrons. In agreement
with theory predictions, plasmas exhibit values of the Coulomb coupling
parameter $\Gamma$ less than 1.


title: Competition between Two Kinds of Correlations in Literary Texts

abstract:
  A theory of additive Markov chains with long-range memory is used for
description of correlation properties of coarse-grained literary texts. The
complex structure of the correlations in texts is revealed. Antipersistent
correlations at small distances, L < 300, and persistent ones at L > 300 define
this nontrivial structure. For some concrete examples of literary texts, the
memory functions are obtained and their power-law behavior at long distances is
disclosed. This property is shown to be a cause of self-similarity of texts
with respect to the decimation procedure.


title: Space charge in drift chambers operated with the Xe,CO2(15%) mixture

abstract:
  Using prototype modules of the ALICE Transition Radiation Detector we
investigate space charge effects and the dependence of the pion rejection
performance on the incident angle of the ionizing particle. The average pulse
height distributions in the drift chambers operated with the Xe,CO2(15%)
mixture provide quantitative information on the gas gain reduction due to space
charge accumulating during the drift of the primary ionization. Our results
demonstrate that the pion rejection performance of a TRD is better for tracks
which are not at normal incidence to the anode wires. We present detailed
simulations of detector signals, which reproduce the measurements and lend
strong support to our interpretation of the measurements in terms of space
charge effects.


title: Drift velocity and gain in argon- and xenon-based mixtures

abstract:
  We present measurements of drift velocities and gains in gas mixtures based
on Ar and Xe, with CO2, CH4, and N2 as quenchers, and compare them with
calculations. In particular, we show the dependence of Ar- and Xe-CO2 drift
velocities and gains on the amount of nitrogen contamination in the gas, which
in real experiments may build up through leaks. A quantification of the Penning
mechanism which contributes to the Townsend coefficients of a given gas mixture
is proposed.


title: Hybrid Particle-Fluid Modeling of Plasmas

abstract:
  There are many interesting physical processes which involve the generation of
high density plasmas in large volumes. However, when modeling these systems
numerically, the large densities and volumes present a significant
computational challenge. One technique for modeling plasma physics, the
particle in cell (PIC) approach, is very accurate but requires increasing
computation time and numerical resolution as the density of the plasma grows.
In this paper we present a new technique for mitigating the extreme
computational load as the plasma density grows by combining existing PIC
methods with a dielectric fluid approach. By using both descriptions in a
hybrid particle-fluid model, we now can probe the physics in large volume, high
density regions. The hybrid method also provides a smooth transition as the
plasma density increases and the ionization fraction grows to values that are
well described by the fluid description alone. We present the hybrid technique
and demonstrate the validity of the physical model by benchmarking against a
simple example with an analytic solution.


title:
Comment on "Geometric absorption of electromagnetic angular momentum",
  C. Konz, G. Benford

abstract:
  The core theorem on which the above paper is centred - that a perfectly
conducting body of revolution absorbs no angular momentum from an axisymmetric
electromagnetic wave field - is in fact a special case of a more general result
in electromagnetic scattering theory. In addition, the scaling of the
efficiency of transfer of angular momentum to an object with the wavelength and
object size merits further discussion. Finally, some comments are made on the
choice of terminology and the erroneous statement that a circularly polarized
plane wave does not carry angular momentum.


title: Effective viscosity of grease ice in linearized gravity waves

abstract:
  Grease ice is an agglomeration of disc-shaped ice crystals, named frazil ice,
which forms in turbulent waters of the Polar Oceans and in rivers as well. It
has been recognized that the properties of grease ice to damp surface gravity
waves could be explained in terms of the effective viscosity of the ice slurry.
This paper is devoted to the study of the dynamics of a suspension of
disc-shaped particles in a gravity wave field. For dilute suspensions,
depending on the strength and frequency of the external wave flow, two
orientation regimes of the particles are predicted: a preferential orientation
regime with the particles rotating in coherent fashion with the wave field, and
a random orientation regime in which the particles oscillate around their
initial orientation while diffusing under the effect of Brownian motion. For
both motion regimes, the effective viscosity has been derived as a function of
the wave frequency, wave amplitude and aspect ratio of the particles. Model
predictions have been compared with wave attenuation data in frazil ice layers
grown in wave tanks.


title: A Billiard-Theoretic Approach to Elementary 1d Elastic Collisions

abstract:
  A simple relation is developed between elastic collisions of freely-moving
point particles in one dimension and a corresponding billiard system. For two
particles with masses m_1 and m_2 on the half-line x>0 that approach an elastic
barrier at x=0, the corresponding billiard system is an infinite wedge. The
collision history of the two particles can be easily inferred from the
corresponding billiard trajectory. This connection nicely explains the classic
demonstrations of the ``dime on the superball'' and the ``baseball on the
basketball'' that are a staple in elementary physics courses. It is also shown
that three elastic particles on an infinite line and three particles on a
finite ring correspond, respectively, to the motion of a billiard ball in an
infinite wedge and on on a triangular billiard table. It is shown how to
determine the angles of these two sets in terms of the particle masses.


title: Oblique amplitude modulation of dust-acoustic plasma waves

abstract:
  Theoretical and numerical studies are presented of the nonlinear amplitude
modulation of dust-acoustic (DA) waves propagating in an unmagnetized three
component, weakly-coupled, fully ionized plasma consisting of electrons,
positive ions and charged dust particles, considering perturbations oblique to
the carrier wave propagation direction. The stability analysis, based on a
nonlinear Schroedinger-type equation (NLSE), shows that the wave may become
unstable; the stability criteria depend on the angle $\theta$ between the
modulation and propagation directions. Explicit expressions for the instability
rate and threshold have been obtained in terms of the dispersion laws of the
system. The possibility and conditions for the existence of different types of
localized excitations have also been discussed.


title:
Linear and nonlinear properties of Rao-dust-Alfv\'en waves in magnetized
  plasmas

abstract:
  The linear and nonlinear properties of the Rao-dust-magnetohydrodynamic
(R-D-MHD) waves in a dusty magnetoplasma are studied. By employing the
inertialess electron equation of motion, inertial ion equation of motion,
Amp\`ere's law, Faraday's law, and the continuity equation in a plasma with
immobile charged dust grains, the linear and nonlinear propagation of
two-dimensional R-D-MHD waves are investigated. In the linear regime, the
existence of immobile dust grains produces the Rao cutoff frequency, which is
proportional to the dust charge density and the ion gyrofrequency. On the other
hand, the dynamics of an amplitude modulated R-D-MHD waves is governed by the
cubic nonlinear Schroedinger equation. The latter has been derived by using the
reductive perturbation technique and the two-timescale analysis which accounts
for the harmonic generation nonlinearity in plasmas. The stability of the
modulated wave envelope against non-resonant perturbations is studied. Finally,
the possibility of localized envelope excitations is discussed.


title: Simple Soluble Molecular Ionization Model

abstract:
  We present a simple exact analytical solution, using the
Weyl-Titchmarsh-Kodaira spectral theorem, for the spectral function of the
one-dimensional diatomic molecule model consisting of two attractive delta
function wells in the presence of a static external electric field. For
sufficiently deep and far apart wells, this molecule supports both an even and
an odd state, and the introduction of a static electric field turns these bound
states into quasi-bound states which are Stark shifted and broadened. The
continuum spectrum also inherits an intricate pattern of resonances which
reflect the competition between resonant scattering between the two atomic
wells and between the linear potential and one or both atomic well(s). All
results are analytic and can be easily plotted. The relation between the large
orders of the divergent perturbative Stark shift series and the
non-perturbative widths of quasi-bound levels is studied.

categories: physics.atom-ph hep-th math-ph math.MP quant-ph


title:
Stratification of the phase clouds and statistical effects of the
  non-Markovity in chaotic time series of human gait for healthy people and
  Parkinson patients

abstract:
  In this work we develop a new method of diagnosing the nervous system
diseases and a new approach in studying human gait dynamics with the help of
the theory of discrete non-Markov random processes. The stratification of the
phase clouds and the statistical non-Markov effects in the time series of the
dynamics of human gait are considered. We carried out the comparative analysis
of the data of four age groups of healthy people: children (from 3 to 10 year
olds), teenagers (from 11 to 14 year oulds), young people (from 21 up to 29
year oulds), elderly persons (from 71 to 77 year olds) and Parkinson patients.
The full data set are analyzed with the help of the phase portraits of the four
dynamic variables, the power spectra of the initial time correlation function
and the memory functions of junior orders, the three first points in the
spectra of the statistical non-Markov parameter. The received results allow to
define the predisposition of the probationers to deflections in the central
nervous system caused by Parkinson's disease. We have found out distinct
differencies between the five submitted groups. On this basis we offer a new
method of diagnostics and forecasting Parkinson's disease.


title:
Tubulin dipole moment, dielectric constant and quantum behavior:
  computer simulations, experimental results and suggestions

abstract:
  We used computer simulation to calculate the electric dipole moments of the
alpha and beta tubulin monomers and dimer and found those to be |palpha|=552D,
|pbeta|=1193D and |palpha-beta|=1740D respectively. Independent surface plasmon
resonance (SPR) and refractometry measurements of the high-frequency dielectric
constant and polarizability strongly corroborated our previous SPR-derived
results giving delta-n/delta-c ~1.800x10^-3 ml/mg. The refractive index of
tubulin was measured to be n_tub ~2.90 and the high frequency tubulin
dielectric constant kappa_tub ~8.41 while the high-frequency polarizability was
found to be alpha_tub ~ 2.1x10^-33 C m^2/V. Methods for the experimental
determination of the low-frequency p are explored as well as ways to test the
often conjectured quantum coherence and entanglement properties of tubulin.
Biobits, bioqubits and other applications to bioelectronics are discussed.


title: Resolution studies of cosmic-ray tracks in a TPC with GEM readout

abstract:
  A large volume TPC is a leading candidate for the central tracking detector
at a future high energy linear collider. To improve the resolution a new
readout based on micro-pattern gas detectors is being developed. Measurements
of the spatial resolution of cosmic-ray tracks in a GEM TPC are presented. We
find that the resolution suffers if the readout pads are too wide with respect
to the charge distribution at the readout plane due to insufficient charge
sharing. For narrow pads of 2 x 6 mm**2 we measure a resolution of 100
micometer at short drift distances in the absence of an axial magnetic field.
The dependence of the spatial resolution as a function of drift distance allows
the determination of the underlying electron statistics. Our results show that
the present technique uses about half the statistical power available from the
number of primary electrons. The track angle effect is observed as expected.


title: Electron-acoustic plasma waves: oblique modulation and envelope solitons

abstract:
  Theoretical and numerical studies are presented of the amplitude modulation
of electron-acoustic waves (EAWs) propagating in space plasmas whose
constituents are inertial cold electrons, Boltzmann distributed hot electrons
and stationary ions. Perturbations oblique to the carrier EAW propagation
direction have been considered. The stability analysis, based on a nonlinear
Schroedinger equation (NLSE), reveals that the EAW may become unstable; the
stability criteria depend on the angle $\theta$ between the modulation and
propagation directions. Different types of localized EA excitations are shown
to exist.


title:
Nonconservative Lagrangian mechanics II: purely causal equations of
  motion

abstract:
  This work builds on the Volterra series formalism presented in [D. W.
Dreisigmeyer and P. M. Young, J. Phys. A \textbf{36}, 8297, (2003)] to model
nonconservative systems. Here we treat Lagrangians and actions as `time
dependent' Volterra series. We present a new family of kernels to be used in
these Volterra series that allow us to derive a single retarded equation of
motion using a variational principle.


title: Plane waves with negative phase velocity in Faraday chiral mediums

abstract:
  The propagation of plane waves in a Faraday chiral medium is investigated.
Conditions for the phase velocity to be directed opposite to the direction of
power flow are derived for propagation in an arbitrary direction; simplified
conditions which apply to propagation parallel to the distinguished axis are
also established. These negative phase-velocity conditions are explored
numerically using a representative Faraday chiral medium, arising from the
homogenization of an isotropic chiral medium and a magnetically biased ferrite.
It is demonstrated that the phase velocity may be directed opposite to power
flow, provided that the gyrotropic parameter of the ferrite component medium is
sufficiently large compared with the corresponding nongyrotropic permeability
parameters.


title: All electromagnetic form factors

abstract:
  The electromagnetic form factors of spin-1/2 particles are known, but due to
historical reasons only half of them are found in many textbooks. Given the
importance of the general result, its model independence, its connection to
discrete symmetries and their violations we made an effort to derive and
present the general result based only on the knowledge of Dirac equation. We
discuss the phenomenology connected directly with the form factors, and spin
precession in external fields including time reversal violating terms. We apply
the formalism to spin-flip synchrotron radiation and suggest pedagogical
projects.


title: Developments for Reference--State One--Particle Density--Matrix Theory

abstract:
  Brueckner orbitals, and the density of the Brueckner reference-state, are
shown to satify the same cusp condition -- involving the nuclear charges -- as
natural- and Hartree--Fock-orbitals. Using the cusp condition, the density of a
determinantal state can be used to determine the external potential, if the
determinantal state is from either Hartee--Fock or Brueckner-orbital theory, as
well as, determinant states obtained by many other formalisms that are defined
by a one-body operator, if a portion of the one-body operator -- the portion
not associated with the kinetic energy or external potential -- generates a
well behaved function when acting on an occupied orbital. Using this
relationship involving a determinant and its external potential, a variation of
Reference--State One--Particle Density--Matrix Theory (physics/0308056) is
formulated, where the trial wavefunctions are universal, in the Kohn-Sham
sense, since they do not depend on the external potential. The resulting
correlation-energy functionals, are also, universal, except for a relatively
small term involving the portion of the expectation value of the external
potential with the trial wavefunctions that appears beyond the first order. The
same approximate energy functionals that were shown to be valid for the
previous v-dependent, Reference--State One--Particle Density--Matrix Theory
(physics/0308084), are shown to be valid for the current approach, except that
the use of the LYP and Colle--Salvetti functional appear more natural within
the current approach, since these functionals are universal ones. And since the
BLYP and B3LYP functionals contain the LYP functional, these approaches are
also better suited with the current approach.


abstract:
  Second harmonic optical coherence tomography, which uses coherence gating of
second-order nonlinear optical response of biological tissues for imaging, is
described and demonstrated. Femtosecond laser pulses were used to excite second
harmonic waves from collagen harvested from rat tail tendon and a reference
nonlinear crystal. Second harmonic interference fringe signals were detected
and used for image construction. Because of the strong dependence of second
harmonic generation on molecular and tissue structures, this technique offers
contrast and resolution enhancement to conventional optical coherence
tomography.


title: Relativistic recursion relations for transition matrix elements

abstract:
  We review some recent results on recursion relations which help evaluating
arbitrary non-diagonal, radial hydrogenic matrix elements of $r^\lambda$ and of
$\beta r^\lambda$ ($\beta$ a Dirac matrix) derived in the context of Dirac
relativistic quantum mechanics. Similar recursion relations were derived some
years ago by Blanchard in the non relativistic limit. Our approach is based on
a generalization of the second hypervirial method previously employed in the
non-relativistic Schr\"odinger case. An extension of the relations to the case
of two potentials in the so-called unshifted case, but using an arbitrary
radial function instead of a power one, is also given. Several important
results are obtained as special instances of our recurrence relations, such as
a generalization to the relativistic case of the Pasternack-Sternheimer rule.
Our results are useful in any atomic or molecular calculation which take into
account relativistic corrections.


title:
Optimal Allocation of Replicas to Processors in Parallel Tempering
  Simulations

abstract:
  The optimal allocation of replicas to a homogeneous or heterogenous set of
processors is derived for parallel tempering simulations on multi-processor
machines. In the general case, it is possible without substantially increasing
wall clock time to achieve nearly perfect utilization of CPU time. Random
fluctuations in the execution times of each of the replicas do not
significantly degrade the performance of the scheduler.


title:
Electron diffraction data on structural transformations in free clucters
  of argon

abstract:
  An electron diffraction technique is used to study the structure of clusters
formed in an isentropically expanding supersonic argon jet. The formation of
the hcp phase with increasing cluster size is reliably detected for the first
time. Observations are made for mean cluster sizes N in the range from 1x10^3
to 8x10^4 atoms/cluster. An analysis of the shape of the diffraction peaks is
carried out. It is found that in the range N <= 2x10^3 atoms/cluster, where the
clusters are icosahedral, the profiles of the diffraction peaks are well
approximated by a Lorentzian. For fcc clusters with N >= 3x10^3 atoms/cluster a
better approximation is the standard Gaussian function. In the case N >= 1x10^4
atoms/cluster one observes peaks of the hcp phase in addition to the fcc peaks.
The intensity of the hcp peaks increases with increasing cluster size, and for
N = 8x10^4 atoms/cluster, the (110), (101), (103), and (202) peaks,
characteristic only for the hcp phase, are clearly registered in addition to
the fcc peaks. A possible mechanism for the formation of the hcp structure in
Ar clusters is proposed.


title: The Thermal Radiation Formula of Planck (1900)

abstract:
  We review the derivation of Planck's Radiation Formula on the light of recent
studies in its centenary. We discuss specially the issue of discreteness,
Planck's opinion on his discovery, and the critical analysis on the
contributions by Ehrenfest, Einstein, Lorentz, etc. We also address the views
of T.S. Kuhn, which conflict with the conventional interpretation that
discontinuty was already found by Planck.


title:
Efficient use of non-equilibrium measurement to estimate free energy
  differences for molecular systems

abstract:
  A promising method for calculating free energy differences Delta F is to
generate non-equilibrium data via ``fast-growth'' simulations or experiments --
and then use Jarzynski's equality. However, a difficulty with using Jarzynski's
equality is that Delta F estimates converge very slowly and unreliably due to
the nonlinear nature of the calculation -- thus requiring large, costly data
sets. Here, we present new analyses of non-equilibrium data from various
simulated molecular systems exploiting statistical properties of Jarzynski's
equality. Using a fully automated procedure, with no user-input parameters, our
results suggest that good estimates of Delta F can be obtained using 6-15 fold
less data than was previously possible. Systematizing and extending previous
work [1], the new results exploit the systematic behavior of bias due to finite
sample size. A key innovation is better use of the more statistically reliable
information available from the raw data.


title: Determination of a Wave Function Functional

abstract:
  In this paper we propose the idea of expanding the space of variations in
standard variational calculations for the energy by considering the wave
function $\psi$ to be a functional of a set of functions $\chi: \psi =
\psi[\chi]$, rather than a function. In this manner a greater flexibility to
the structure of the wave function is achieved. A constrained search in a
subspace over all functions $\chi$ such that the wave function functional
$\psi[\chi]$ satisfies a constraint such as normalization or the Fermi-Coulomb
hole charge sum rule, or the requirement that it lead to a physical observable
such as the density, diamagnetic susceptibility, etc. is then performed. A
rigorous upper bound to the energy is subsequently obtained by variational
minimization with respect to the parameters in the approximate wave function
functional. Hence, the terminology, the constrained-search variational method.
The \emph{rigorous} construction of such a constrained-search--variational wave
function functional is demonstrated by example of the ground state of the
Helium atom.


title: Ion energy balance during fast wave heating in TORE SUPRA

abstract:
  Direct coupling of the fast magnetosonic wave to the electrons has been
studied on the tokamak TORE SUPRA. Preliminary experiments were dedicated to
optimise the scenario for Fast Wave Electron Heating (FWEH) and Current Drive
(FWCD). In a first part, thermal kinetic and diamagnetic energy are compared
when fast wave is applied to the plasma in two different regimes: 1/ the
minority hydrogen heating scenario (ICRH), 2/ the direct electron damping.
Effects of ion resonant layers, marginally present in the plasma in the later
regime (FWEH), is then presented and discussed.


title:
Hydrodynamical interpretation of quantum mechanics: the momentum
  distribution

abstract:
  The quantum mechanics is considered to be a partial case of the stochastic
system dynamics. It is shown that the wave function describes the state of
statistically averaged system $<\mathcal{S}_{st}>$, but not that of the
individual stochastic system $\mathcal{S}_{st}$. It is a common practice to
think that such a construction of quantum mechanics contains hidden variables,
and it is incompatible with the von Neumann's theorem on hidden variables. It
is shown that the original conditions of the von Neumann's theorem are not
satisfied. In particular, the quantum mechanics cannot describe the particle
momentum distribution. The distribution $w(\mathbf{p}) =| \psi_{p%}| ^{2}$ is
not a particle momentum distribution at the state $\psi $, because it cannot be
attributed to a wave function. It is closer to the mean momentum distribution,
although the two distributions do not coincide exactly.


title: An Elementary Derivation of the Harmonic Oscillator Propagator

abstract:
  The harmonic oscillator propagator is found straightforwardly from the free
particle propagator, within the imaginary-time Feynman path integral formalism.
The derivation presented here is extremely simple, requiring only elementary
mathematical manipulations and no clever use of Hermite polynomials,
annihilation & creation operators, cumbersome determinant evaluations or any
kind of involved algebra.


title: Using a neural network approach for muon reconstruction and triggering

abstract:
  The extremely high rate of events that will be produced in the future Large
Hadron Collider requires the triggering mechanism to take precise decisions in
a few nano-seconds. We present a study which used an artificial neural network
triggering algorithm and compared it to the performance of a dedicated
electronic muon triggering system. Relatively simple architecture was used to
solve a complicated inverse problem. A comparison with a realistic example of
the ATLAS first level trigger simulation was in favour of the neural network. A
similar architecture trained after the simulation of the electronics first
trigger stage showed a further background rejection.


title: Detection of Vacuum Birefringence with Intense Laser Pulses

abstract:
  We propose a novel technique that promises hope of being the first to
directly detect a polarization in the quantum electrodynamic (QED) vacuum. The
technique is based upon the use of ultra-short pulses of light circulating in
low dispersion optical resonators. We show that the technique circumvents the
need for large scale liquid helium cooled magnets, and more importantly avoids
the experimental pitfalls that plague existing experiments that make use of
these magnets. Likely improvements in the performance of optics and lasers
would result in the ability to observe vacuum polarization in an experiment of
only a few hours duration.

categories: physics.optics hep-ex physics.gen-ph physics.ins-det


title: Two complementary representations of a scale-free network

abstract:
  Several studies on real complex networks from different fields as biology,
economy, or sociology have shown that the degree of nodes (number of edges
connected to each node) follows a scale-free power-law distribution like
$P(k)\approx k^{-\gamma}$, where $P(k)$ denotes the frequency of the nodes that
are connected to $k$ other nodes. Here we have carried out a study on
scale-free networks, where a line graph transformation (i.e., edges in an
initial network are transformed into nodes) is applied to a power-law
distribution. Our results indicate that a power-law distribution as
$P(k)\approx k^{-\gamma +1}$ is found for the transformed network together with
a peak for low-degree nodes. In the present work we show a parametrization of
this behaviour and discuss its application to real networks as metabolic
networks, protein-protein interaction network and World Wide Web.

categories: physics.bio-ph cond-mat.dis-nn cond-mat.stat-mech physics.data-an


title:
Ultrafast Resonant Polarization Interferometry: Towards the First Direct
  Detection of Vacuum Polarization

abstract:
  Vacuum polarization, an effect predicted nearly 70 years ago, is still yet to
be directly detected despite significant experimental effort. Previous attempts
have made use of large liquid-helium cooled electromagnets which inadvertently
generate spurious signals that mask the desired signal. We present a novel
approach for the ultra-sensitive detection of optical birefringence that can be
usefully applied to a laboratory detection of vacuum polarization. The new
technique has a predicted birefringence measurement sensitivity of $\Delta n
\sim 10^{20}$ in a 1 second measurement. When combined with the extreme
polarizing fields achievable in this design we predict that a vacuum
polarization signal will be seen in a measurement of just a few days in
duration.

categories: physics.ins-det hep-ex physics.gen-ph physics.optics


title:
Internal vs. External Conductivity of a Dense Plasma: Many-particle
  theory and simulations

abstract:
  In the long-wavelength limit k=0, the response function has been investigated
with respect to the external and internal fields which is expressed by the
external and internal conductivity, respectively. Molecular dynamics (MD)
simulations are performed to obtain the current-current correlation function
and the dynamical collision frequency which are compared with analytical
expressions. Special attention is given to the dynamical collision frequency
and the description of plasma oscillations in the case of k=0. The relation
between the external and internal conductivity and to the current-current
correlation function is analyzed.


title: An hypersphere model of the Universe - The dismissal of dark matter

abstract:
  One can make the very simple hypothesis that the Universe is the inside of an
hypersphere in 4 dimensions, where our 3-dimensional world consists of
hypersurfaces at different radii. Based on this assumption it is possible to
show that Universe expansion at a rate corresponding to flat comes as a direct
geometrical consequence without intervening critical density; any mass density
is responsible for opening the Universe and introduces a cosmological constant.
Another consequence is the appearance of inertia swirls of expanding matter,
which can explain observed velocities around galaxies, again without the
intervention of dark matter. When restricted to more everyday situations the
model degenerates in what has been called 4-dimensional optics; in the paper
this is shown to be equivalent to general relativity in all static isotropic
metric situations. In the conclusion some considerations bring the discussion
to the realm of 4D wave optics.


title: Fastest learning in small world neural networks

abstract:
  We investigate supervised learning in neural networks. We consider a
multi-layered feed-forward network with back propagation. We find that the
network of small-world connectivity reduces the learning error and learning
time when compared to the networks of regular or random connectivity. Our study
has potential applications in the domain of data-mining, image processing,
speech recognition, and pattern recognition.


title:
Unified theory of bound and scattering molecular Rydberg states as
  quantum maps

abstract:
  Using a representation of multichannel quantum defect theory in terms of a
quantum Poincar\'e map for bound Rydberg molecules, we apply Jung's scattering
map to derive a generalized quantum map, that includes the continuum. We show,
that this representation not only simplifies the understanding of the method,
but moreover produces considerable numerical advantages. Finally we show under
what circumstances the usual semi-classical approximations yield satisfactory
results. In particular we see that singularities that cause problems in
semi-classics are irrelevant to the quantum map.


title: Self-generated Self-similar Traffic

abstract:
  Self-similarity in the network traffic has been studied from several aspects:
both at the user side and at the network side there are many sources of the
long range dependence. Recently some dynamical origins are also identified: the
TCP adaptive congestion avoidance algorithm itself can produce chaotic and long
range dependent throughput behavior, if the loss rate is very high. In this
paper we show that there is a close connection between the static and dynamic
origins of self-similarity: parallel TCPs can generate the self-similarity
themselves, they can introduce heavily fluctuations into the background traffic
and produce high effective loss rate causing a long range dependent TCP flow,
however, the dropped packet ratio is low.

categories: physics.data-an cond-mat.other cs.NI nlin.AO