March 2004 arXiv papers — page 9

S. Kuperstein

We discuss a regular non-supersymmetric deformation of the Klebanov-Strassler solution related to gaugino mass terms in the dual gauge theory. We also describe the Penrose limit of the new background and the corresponding plane wave string theory.

V. V. Braguta, A. I. Onishchenko

We present predictions for rho-meson form factors obtained from the analysis of QCD sum rules in next-to-leading order of perturbation theory. The radiative corrections turn out to be sizeable and should be taken into account in rigorous theoretical analysis.

Kazunori Itakura

The proton structure function F_2(x,Q^2) for x < 0.01 and 0.045< Q^2 < 45 GeV^2, measured in the deep inelastic scattering at HERA, can be well described within the framework of the Color Glass Condensate.

O. V. Tarasov

The Gröbner basis technique for calculating Feynman diagrams proposed in [O.V. Tarasov, Acta Physica Polonica, v. B29 (1998) 2655] is applied to the two-loop propagator type integrals with arbitrary masses and momentum. We describe the derivation of Gröbner bases for all integrals with 1PI topologies and present elements of the Gröbner bases.

Kai-Peer O. Diener

We present an estimate of the electron to muon conversion cross section in fixed-target elastic electron scattering. The matrix element $<μ| j_\mathrm{em}^μ(0) | e>$ is calculated analytically in two scenarios introducing suitable approximations. We consider on the one hand side the case of three light Dirac neutrinos with CKM-type leptonic mixing and on the

H. -W. Hammer, Ulf-G. Meißner

In the light of the new data on the various neutron and proton electromagnetic form factors taken in recent years, we update the dispersion-theoretical analysis of the nucleon electromagnetic form factors from the mid-nineties. The parametrization of the spectral functions includes constraints from unitarity, perturbative QCD, and recent measurements of the

H. B. Nielsen, Y. Takanishi

We consider the breaking of the global conservation of gauge field charges which are commonly thought to survive the spontaneous breakdown of gauge symmetry brought about by Kalb-Ramond fields. Depending on the dilaton field and also the size of the compactifying space, the global charge breaking may take place due to world sheet instantons. In going to 3+1

L3 Collaboration

Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gam

Ng Ibohal

In this paper, by applying Newman-Janis algorithm in spherical symmetric metrics, a class of embedded rotating solutions of field equations is presented. These solutions admit non-perfect fluids

Alexander Poltorak

A covariant reformulation of General Relativity is briefly considered from three points of view: geometrodynamics, Lagrange-Euler field theory, and gauge field theory. From a geometrodynamics perspective, a definition of the reference frame as a differential manifold with an affine connection results in separation of the respective contributions of inertial

Silvio M. Duarte Queiros

In this paper one studies the distribution of log-returns (tick-by-tick) in the Lisbon stock market and shows that it is well adjusted by the solution of the equation, {$\frac{dp_{x}}{d| x|}=-β_{q^{\prime }}p_{x}^{q^{\prime}}-(β_{q}-β_{q^{\prime}}) p_{x}^{q}$}, which corresponds to a generalization of the differential equation which has as solution the power

R. Casalini, C. M. Roland

Classification of glass-forming liquids based on the dramatic change in their properties upon approach to the glassy state is appealing, since this is the most conspicuous and often-studied aspect of the glass transition. Herein, we show that a generalized scaling, log tau proportional to T^(-1)V^(-gamma), where gamma is a material-constant, yields superposi

R. Rothenstein, K. Pawelzik

It has been assumed that arbitrage profits are not possible in efficient markets, because future prices are not predictable. Here we show that predictability alone is not a sufficient measure of market efficiency. We instead propose to measure inefficiencies of markets in terms of the maximal profit an ideal trader can take out from a market. In a stock mark

Hokky Situngkir, Yohanes Surya

Artificial Neural Network Model for prediction of time-series data is revisited on analysis of the Indonesian stock-exchange data. We introduce the use of Multi-Layer Perceptron to percept the modified Poincare-map of the given financial time-series data. The modified Poincare-map is believed to become the pattern of the data that transforms the data in time

Beatrix M. Schulz, Steffen Trimper, Michael Schulz

We study the dynamics of a spin facilitated Ising model with long range kinetic constraints. To formulate those restrictions within an analytical approach we introduce the size of a kinetic active environment of a given spin. Based on a Master equation in second quantized form, the spin-autocorrelation function is calculated. It exhibits a pronounced slow dy

V. Janis, J. Kolorenc

We discuss conservation of probability in noniteracting disordered electron systems. We argue that although the norm of the electron wave function is conserved in individual realizations of the random potential, we cannot extend this conservation law easily to configurationally averaged systems in the thermodynamic limit. A direct generalization of the norm

Bernard Placais, Norbert Lutke-Entrup, Joel Bellessa, Patrice Mathieu

We present a theoretical and experimental study of the peak effect in the surface pinning of vortices. It is associated with a sharp transition in the vortex slippage length which we relate to a crossover from a weakly disordered crystal to a surface glass state. Experiments are performed on ion-beam etched Nb crystals. The slippage length is deduced from 1k

B. Wemmenhove, N. S. Skantzos, A. C. C. Coolen

We study extremely diluted spin models of neural networks in which the connectivity evolves in time, although adiabatically slowly compared to the neurons, according to stochastic equations which on average aim to reduce frustration. The (fast) neurons and (slow) connectivity variables equilibrate separately, but at different temperatures. Our model is exact

Jörg Lehmann, Sigmund Kohler, Volkhard May, Peter Hänggi

The influence of an electron-vibrational coupling on the laser control of electron transport through a molecular wire that is attached to several electronic leads is investigated. These molecular vibrational modes induce an effective electron-electron interaction. In the regime where the wire electrons couple weakly to both the external leads and the vibrati

R. Onofrio, C. Presilla

The study of low density, ultracold atomic Fermi gases is a promising avenue to understand fermion superfluidity from first principles. One technique currently used to bring Fermi gases in the degenerate regime is sympathetic cooling through a reservoir made of an ultracold Bose gas. We discuss a proposal for trapping and cooling of two-species Fermi-Bose mi

Pierre-Henri Chavanis, Philippe Laurencot, Mohammed Lemou

We use the Chapman-Enskog method to derive the Smoluchowski equation from the Kramers equation in a high friction limit. We consider two main extensions of this problem: we take into account a uniform rotation of the background medium and we consider a generalized class of Kramers equations associated with generalized free energy functionals. We mention appl

S. Pailhes, Y. Sidis, P. Bourges, V. Hinkov

A detailed inelastic neutron scattering study of the high temperature superconductor $\rm YBa_2Cu_3O_{6.85}$ provides evidence of new resonant magnetic features, in addition to the well known resonant mode at 41 meV: (i) a commensurate magnetic resonance peak at 53 meV with an even symmetry under exchange of two adjacent $\rm CuO_2$ layers; and (ii) high ene

J. Dziarmaga, A. Smerzi, W. H. Zurek, A. R. Bishop

We study the non-equilibrium dynamics of the zero temperature Mott insulator- superfluid quantum phase transition in a lattice of weakly coupled Bose-Einstein condensates. We show that crossing the critical point from the insulating to the superfluid phase at a finite rate results in a finite dispersion of current. Viceversa, crossing the critical point from

G. Caballero, A. Lindner, G. Ovarlez, G. Reydellet

We present here the preliminary results obtained for two experiments on randomly agitated granular assemblies using a novel way of shaking. First we discuss the transport properties of a 2D model system undergoing classical shaking that show the importance of large scale dynamics for this type of agitation and offer a local view of the microscopic motions of

Takeshi Nishimatsu, Takatoshi Hashimoto, Hiroshi Mizuseki, Yoshiyuki Kawazoe

An ab initio structure optimization technique is newly developed to determine the valley line on a total-energy surface for zone-center distortions of ferroelectric perovskite oxides and is applied to barium titanate BaTiO3 and lead titanate PbTiO3. The proposed technique is an improvement over King-Smith and Vanderbilt&#39;s scheme [Phys. Rev. B 49, p.5828

Y. Yamamoto, T. Miura, T. Teranishi, M. Miyake

We report the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agreement with the results obtained by conven

A. Bernui, G. I. Gomero, B. Mota, M. J. Reboucas

The pair separations statistical methods devised to detect the topology of the universe rely on the accurate knowledge of the three-dimensional positions of the cosmic sources. The determination of these positions, however, involves inevitable observational uncertainties. The only significant (measurable) sign of a nontrivial topology in PSH&#39;s was shown

L. Nicastro, J. J. M. in &#39;t Zand, L. Amati, E. Mazets

GRB 020410 is by far the longest gamma-ray burst (with a duration of about 1600 s) to have been followed up from the X-ray through the radio regime. Afterglow emission was detected in X-rays and at optical wavelengths while no emission was detected at 8 GHz brighter than 120 microJy. The decaying X-ray afterglow, back extrapolated to 11 hr after the burst, h

Ryuichi Kurosawa, Tim J. Harries, Matthew R. Bate, Neil H. Symington

We present three-dimensional Monte Carlo radiative transfer models of a very young (<10^5 years old) low mass (50 Msun) stellar cluster containing 23 stars and 27 brown dwarfs. The models use the density and the stellar mass distributions from the large-scale smoothed particle hydrodynamics (SPH) simulation of the formation of a low-mass stellar cluster by B

O. R. Prouton, A. Bressan, M. Clemens, A. Franceschini

We have performed 23 GHz VLA observations of 7 compact, luminous infrared galaxies, selected to have evidence of starburst activity. New and published multi-frequency data are combined to obtain the spectral energy distributions of all 7 galaxies from the near-infrared to the radio (at 1.4 GHz). These SEDs are compared with new models, for dust enshrouded ga

S. Mathis, A. Palacios, J. -P. Zahn

We review various prescriptions which have been proposed for the turbulent transport of matter and angular momentum in differentially rotating stellar radiation zones. A new prescription is presented for the horizontal transport associated with the anisotropic shear turbulence which is produced by the differential rotation in latitude; this `beta-viscosity&#

David Langlois

This talk presents an overview of the brane cosmology scenario, based on the idea that our Universe is a 3-brane embedded in a five-dimensional anti-de Sitter bulk space-time. Special emphasis is put on the novel features of this scenario: an unconventional cosmological evolution at high energy densities, i.e. in the early universe, and dark radiation, that

P. G. Jonker, E. Gallo, V. Dhawan, M. Rupen

Obtaining simultaneous radio and X-ray data during the outburst decay of soft X-ray transients is a potentially important tool to study the disc - jet connection. Here we report results of the analysis of (nearly) simultaneous radio (VLA or WSRT) and Chandra X-ray observations of XTE J1908+094 during the last part of the decay of the source after an outburst

Yukikatsu Terada, Manabu Ishida, Kazuo Makishima

In order to confirm the anisotropic effect of resonance photons in hot accretion columns on white dwarfs in magnetic cataclysmic variables, proposed by Terada etal (2001), systematic studies with ASCA of 7 polars and 12 intermediate polars are performed. The equivalent widths of He-like Fe K$_α$ line of polars are found to be systematically modulated at thei

Eric S. Perlman, Timothy Daugherty, Anuradha Koratkar, Grzegorz Madejski

We report results from {\it XMM-Newton} observations of thirteen X-ray bright BL Lacertae objects, selected from the {\it Einstein} Slew Survey sample. The spectra are generally well fit by power-law models, with four objects having hard ($α<1; F_ν\propto ν^{-α}$) spectra that indicates synchrotron peaks at $>5$ keV. None of our spectra show line features, i

Y. Alibert, C. Mordasini, W. Benz

We extend the core-accretion model of giant gaseous planets by Pollack et al. (\cite{P96}) to include migration, disc evolution and gap formation. Starting with a core of a fraction of an Earth&#39;s mass located at 8 AU, we end our simulation with the onset of runaway gas accretion when the planet is at 5.5 AU 1 Myr later. This timescale is about a factor t

S. Hoefner, R. Gautschy-Loidl, B. Aringer, W. Nowotny

Cool giant stars are highly dynamical objects, and complex micro-physical processes play an important role in their extended atmospheres and winds. The interpretation of observations, and in particular of high-resolution IR spectra, requires realistic self-consistent model atmospheres. Current dynamical models include rather detailed micro-physics, and the r

J. Southworth, P. F. L. Maxted, B. Smalley

We derive absolute dimensions of the early B-type detached eclipsing binary V453 Cygni (B0.4 IV + B0.7 IV, P=3.89d), a member of the open cluster NGC 6871. From the analysis of new, high-resolution, spectroscopy and the UBV light curves of Cohen (1974) we find the masses to be 14.36 +/- 0.20 and 11.11 +/- 0.13 Msun, the radii to be 8.55 +/- 0.06 and 5.49 +/-

Masako Nishiyama, Masa-aki Morita, Masahiro Morikawa

We study a cosmological model in which the boson dark matter gradually condensates into dark energy. Negative pressure associated with the condensate yields the accelerated expansion of the Universe and the rapid collapse of the smallest scale fluctuations into many black holes, which become the seeds of the first galaxies. The cycle of gradual sedimentation

M. Schuessler, D. Schmitt

We address the question whether the properties of the observed latitude-time diagram of sunspot occurence (the butterfly diagram) provide evidence for the operation of a flux-transport dynamo, which explains the migration of the sunspot zones and the period of the solar cycle in terms of a deep equatorward meridional flow. We show that the properties of the

Paul M. O&#39;Neill, Kirpal Nandra, Iossif E. Papadakis, T. Jane Turner

The Tartarus database contains products for 529 ASCA observations of active galactic nuclei. We have been updating Tartarus to include observing sequences conducted after 1999 January. The revised database will contain products for 375 objects, with a total of 614 observing sequences. We have begun a systematic timing analysis of the Tartarus light curves. W

Paolo Cea

We discuss a general mechanism which allows to explain naturally both radio and high energy emission by pulsars. We also discuss the plasma distribution in the region surrounding the pulsar, the pulsar wind and the formation of jet along the magnetic axis. We suggest a plausible mechanism to generate pulsar proper motion velocities.

Renaud Papoular

Published interpretations of the relative intensity variations of the Unidentified Infrared Bands (UIBs) and their underlying continuum are discussed. An alternative model is proposed, in which a single carrier for both emits a) mostly a continuum when it is electronically excited by photons (visible or UV), or b) exclusively the UIBs, when only chemical ene

Janne Holopainen, Chris Flynn

We place observational constraints on a recently proposed Galactic population, dubbed the shroud (Gyuk & Gates 1999, Gates & Gyuk 2001). The shroud would be a very thick Galactic disk of low luminosity objects, most likely old white dwarfs, proposed to explain the optical depth seen in microlensing surveys towards the Magellanic clouds. The shroud is a simpl

Scott Funkhouser

If Mach&#39;s Principle explains the Newtonian inertial reaction to acceleration then the role of the &#39;fixed stars&#39; should also be manifest through Hamilton&#39;s formulation of mechanics. This consistency may be achieved if the expression for relativistic energy contains a cosmological coefficient that is (currently) equal to one. The presence of th

Evelise Gausmann, Reuven Opher

This paper has been withdrawn by the authors for future revision.

V. E. Kuzmichev, V. V. Kuzmichev

The quantum model of the homogeneous and isotropic universe predicts logarithmic-law dependence of coordinate distance to source on redshift z which is in good agreement with type Ia supernovae and radio galaxies observations for the redshift range z = 0.01 - 1.8. A comparison with phenomenological models with dark energy in the form of cosmological constant

HongSheng Zhao

How fast a satellite decays its orbit depends on how slowly its mass is lost by tide. Motivated by inner halo satellite remnants like the Sgr and Omega Cen, we develop fully analytical models to study the orbital decay and tidal massloss of satellites. The orbital decay rate is often severely overestimated if applying the ChandraSekhar&#39;s formula without

Dan Israel, Costas Kounnas, Ari Pakman, Jan Troost

We compute the partition function of the supersymmetric two-dimensional Euclidean black hole geometry described by the SL(2,R)/U(1) superconformal field theory. We decompose the result in terms of characters of the N=2 superconformal symmetry. We point out puzzling sectors of states besides finding expected discrete and continuous contributions to the partit

Thomas Appelquist, L. C. R. Wijewardhana

We review the phase structure of a three-dimensional, non-compact Abelian gauge theory (QED3) as a function of the number $N$ of 4-component massless fermions. There is a critical $N_{c}$ up to which there is dynamical fermion mass generation and an associated global symmetry breaking. We discuss various approaches to the determination of $N_c$, which lead t

Michal Horodecki, Aditi Sen De, Ujjwal Sen

Impossibility of cloning and deleting of unknown states are important restrictions on processing of information in the quantum world. On the other hand, a known quantum state can always be cloned or deleted. However if we restrict the class of allowed operations, there will arise restrictions on the ability of cloning and deleting machines. We have shown tha

Einan Gardi

The inclusive spectra of radiative and semi-leptonic B-meson decays near the endpoint is computed taking into account renormalons in the Sudakov exponent (Dressed Gluon Exponentiation). In this framework we demonstrate the factorization of decay spectra into hard, jet and soft functions and discuss the universality of the latter two. Going beyond perturbatio

Jean-François Marckert, Abdelkader Mokkadem

Consider $q_n$ a random pointed quadrangulation chosen equally likely among the pointed quadrangulations with $n$ faces. In this paper we show that, when $n$ goes to $+\infty$, $q_n$ suitably normalized converges weakly in a certain sense to a random limit object, which is continuous and compact, and that we name the Brownian map. The same result is shown fo

S. Shankaranarayanan, L. Sriramkumar

Due to the tremendous red-shift that occurs during the inflationary epoch in the early universe, it has been realized that trans-Planckian physics may manifest itself at energies much lower than the Planck energy. The presence of a fundamental scale suggests that local Lorentz invariance may be violated at sufficiently high energies. Motivated by this possib

Dejan Stojkovic, Katherine Freese

We propose a solution to the cosmological monopole problem: Primordial black holes, produced in the early universe, can accrete magnetic monopoles before the relics dominate the energy density of the universe. These small black holes quickly evaporate and thereby convert most of the monopole energy density into radiation. We estimate the range of parameters

R. Jackiw

When the 3-dimensional gravitational Chern-Simons term is reduced to two dimensions a dilaton-like gravity theory emerges. Its solutions involve kinks, which therefore describe 3-dimensional, conformally flat spaces.

E949 Collaboration, A. V. Artamonov

An additional event near the upper kinematic limit for K+ to pi+ nu nubar has been observed by Experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is B(K+ to pi+ nu nubar)= 1.47 (+1.30, - 0.89) x 10-10 based on three events observed in the pion momentum region 211<P<229 MeV/c. At the measured cen

Per-Kristian Rekdal, Stefan Scheel, Peter L. Knight, E. A. Hinds

We derive the spontaneous and thermal spin-flip rates for a neutral two-level ultra-cold atom that is coupled to a magnetic field. We apply this theory to an atom in the vicinity of a 2-layer cylindrical absorbing dielectric body surrounded by an unbounded homogeneous medium. An analytical expression is obtained for the spontaneous and thermal spin-flip rate

Thomas Gregoire, Matthew D. Schwartz, Yael Shadmi

We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show

Weimin Chen

Each lens space has a canonical contact structure which lifts to the distribution of complex lines on the three-sphere. In this paper, we show that a symplectic homology cobordism between two lens spaces, which is given with the canonical contact structure on the boundary, must be diffeomorphic to the product of a lens space with the unit interval. As one of

Lahcen Ouchti

We established the rate of convergence in the central limit theorem for stopped sums of a class of martingale difference sequences.

V. Guritanu, W. Goldacker, F. Bouquet, Y. Wang

We present new specific heat data for Nb3Sn, a well-known technically applied superconductor with a critical temperature T_c ~ 18 K, in the temperature range from 1.2 to 200 K in zero magnetic field, and from 1.5 to 22 K in fields H <= 16 T. The particularly dense and homogeneous polycrystalline sample used for this study is characterized in detail. We deter

S. M. Kazakov, N. D. Zhigadlo, M. Brühwiler, B. Batlogg

RbOs2O6, the third superconducting pyrochlore oxide (known so far), has been synthesized by encapsulation and by high pressure techniques. Suitable post chemical treatment of the as-prepared sample allowed us to eliminate the impurity phases. Bulk superconductivity with Tc=6.4 K was observed in magnetisation and specific heat measurements. The transition tem

A. I. Olemskoi, D. O. Kharchenko, I. A. Knyaz&#39;

A general approach to consider spatially extended stochastic systems with correlations between additive and multiplicative noises subject to nonlinear damping is developed. Within modified cumulant expansion method, we derive an effective Fokker-Planck equation whose stationary solutions describe a character of ordered state. We find that fluctuation cross-c

J. A. Aguilar-Saavedra

Selectron decays constitute a source of 100% polarised neutralinos, whose helicity is fixed by the charge and &#34;chirality&#34; of the decaying selectron. In SUSY scenarios where the second neutralino X_2^0 has three-body decays, the cascade decay e_L -> e X_2^0 -> e X_1^0 mu+ mu- provides a clean place to study CP violation in the neutralino sector, throu

Andre Lukas, P. M. Saffin

We analyze supersymmetric solutions of M-theory based an a seven-dimensional internal space with SU(3) structure and a four-dimensional maximally symmetric space. The most general supersymmetry conditions are derived and we show that a non-vanishing cosmological constant requires the norms of the two internal spinors to differ. We find explicit local solutio

Rong-Gen Cai, Hongsheng Zhang

We discuss an inflation model, in which the inflation is driven by a single scalar field with exponential potential on a warped DGP brane. In contrast to the power law inflation in standard model, we find that the inflationary phase can exit spontaneously without any mechanism. The running of the index of scalar perturbation spectrum can take an enough large

Badis Ydri

Noncommutative U(1) gauge theory on the Moyal-Weyl space ${\bf R}^2{\times}{\bf R}^2_θ$ is regularized by approximating the noncommutative spatial slice ${\bf R}^2_θ$ by a fuzzy sphere of matrix size $L$ and radius $R$ . Classically we observe that the field theory on the fuzzy space ${\bf R}^2{\times}{\bf S}^2_L$ reduces to the field theory on the Moyal-Wey

R. P. Malik

In the framework of augmented superfield approach, we provide the geometrical origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST charges and a non-nilpotent bosonic charge. Together, these local and conserved charges turn out to be responsible for a clear and cogent definition of the Hodge decomposition theorem in the quantum Hil

Christophe Le Poncin-Lafitte, Bernard Linet, Pierre Teyssandier

In suitably chosen domains of space-time, the world function may be a powerful tool for modelling the deflection of light and the time/frequency transfer. In this paper we work out a recursive procedure for expanding the world function into a perturbative series of ascending powers of the Newtonian gravitational constant G. We show rigorously that each pertu

S. A. Kudryavtsev

In this paper the three-dimensional divisorial contractions $f\colon Y\to (X\ni P)$ are classified provided that $\Exc f=E$ is an irreducible divisor, $f(E)=P$, the variety $Y$ has canonical singularities and $(X\ni P)$ is a toric terminal singularity.

F. Zamponi, G. Ruocco, L. Angelani

By numerical simulation of a Lennard-Jones like liquid driven by a velocity gradient γwe test the fluctuation relation (FR) below the (numerical) glass transition temperature T_g. We show that, in this region, the FR deserves to be generalized introducing a numerical factor X(T,γ)<1 that defines an ``effective temperature&#39;&#39; T_{FR}=T/X. On the same sy

Nicolas Bouche, James D. Lowenthal

[Abridged] We present out results on the cross-correlation of Lyman break galaxies (LBGs) around three damped \Ly absorbers (DLAs) at redshift three from deep multi-band MOSAIC images obtained at the KPNO 4m. The large area of the MOSAIC images, 0.31 $°^2$ allows us to probe the clustering of LBGs on scales up to 20 Mpc co-moving to test whether DLA halos ar

M. Creze, V. Mohan, A. C. Robin, C. Reyle

Having ruled out the possibility that stellar objects are the main contributor of the dark matter embedding galaxies, microlensing experiments cannot exclude the hypothesis that a significant fraction of the Milky Way dark halo might be made of MACHOs with masses in the range $0.5-0.8 \msun$. Ancient white dwarfs are generally considered the most plausible c

Tamir Boaz

A universal quantum gate is introduced for tensors of vector spaces. By using integer powers of such a gate and by using classical reversible gates one can approximate any element of the unitary group to any accuracy needed. The proof uses a version of Kronecker&#39;s theory and the structure of the Bloch sphere for tensors.

Y. Sumino

The static QCD potential is analyzed in operator-product-expansion within potential-NRQCD framework when r << 1/Lambda_{QCD}. We show that the leading short-distance contribution to the potential, defined as a perturbatively computable Wilson coefficient, can be expressed, up to O(r^2), as a ``Coulomb+linear&#39;&#39; potential. It coincides with the ``Coulo

Eloy Ayón-Beato, Alberto García

We present a regular class of exact black hole solutions of Einstein equations coupled with a nonlinear electrodynamics source. For weak fields the nonlinear electrodynamics becomes the Maxwell theory, and asymptotically the solutions behave as the Reissner-Nordström one. The class is endowed with four parameters, which can be thought of as the mass $m$, cha

Eloy Ayón-Beato, Cristián Martínez, Jorge Zanelli

A nontrivial scalar field configuration of vanishing energy-momentum is reported. These matter configurations have no influence on the metric and therefore they are not be &#34;detected&#34; gravitationally. This phenomenon occurs for a time-dependent nonminimally coupled and self-interacting scalar field on the 2+1 (BTZ) black hole geometry. We conclude tha

A. Lazzarini, S. Bose, P. Fritschel, M. McHugh

This article derives an optimal (i.e., unbiased, minimum variance) estimator for the pseudo-detector strain for a pair of co-located gravitational wave interferometers (such as the pair of LIGO interferometers at its Hanford Observatory), allowing for possible instrumental correlations between the two detectors. The technique is robust and does not involve a

Eloy Ayón-Beato, Cristián Martínez, Jorge Zanelli

All three-dimensional matter-free spacetimes with negative cosmological constant, compatible with cyclic symmetry are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2) x R isometry, and the self-dual Coussaert-Henneaux spacetimes, with isometry groups SO(2) x SO(2,1) or SO(2) x SO(2).

Barbara Synak, Michal Horodecki

We investigate classical information deficit: a candidate for measure of classical correlations emerging from thermodynamical approach initiated in [Phys. Rev. Lett 89, 180402]. It is defined as a difference between amount of information that can be concentrated by use of LOCC and the information contained in subsystems. We show nonintuitive fact, that one w

Jaromir Fiurasek

We investigate the probabilistic cloning and purification of quantum states. The performance of these probabilistic operations is quantified by the average fidelity between the ideal and actual output states. We provide a simple formula for the maximal achievable average fidelity and we explictly show how to construct a probabilistic operation that achieves

M. -Y. Ye, Dong Sun, Y. -S. Zhang, G. -C. Guo

We consider a two-qubit unitary operation along with arbitrary local unitary operations acts on a two-qubit pure state, whose entanglement is C_0. We give the conditions that the final state can be maximally entangled and be non-entangled. When the final state can not be maximally entangled, we give the maximal entanglement C_max it can reach. When the final

Sergio De Filippo, Filippo Maimone

The localizing properties and the entropy production of the Newtonian limit of a nonunitary version of fourth order gravity are analyzed. It is argued that pure highly unlocalized states of the center of mass motion of macroscopic bodies rapidly evolve into unlocalized ensembles of highly localized states. The localization time and the final entropy are esti

Hiroo Azuma

In this paper, we study the quantum computation realized by an interaction-free measurement (IFM). Using Kwiat et al.&#39;s interferometer, we construct a two-qubit quantum gate that changes one particle&#39;s trajectory according to whether or not the other particle exists in the interferometer. We propose a method for distinguishing Bell-basis vectors, eac

Francesco Rao, Amedeo Caflisch

The conformation space of a 20-residue antiparallel $β$-sheet peptide, sampled by molecular dynamics simulations, is mapped to a network. Conformations are nodes of the network, and the transitions between them are links. The conformation space network describes the significant free energy minima and their dynamic connectivity without projections into arbitr

Christophe Soule

We discuss properties which must be satisfied by a genetic network in order for it to allow differentiation. These conditions are expressed as follows in mathematical terms. Let $F$ be a differentiable mapping from a finite dimensional real vector space to itself. The signs of the entries of the Jacobian matrix of $F$ at a given point $a$ define an interacti

R. Jackiw

On the fiftieth anniversary of Yang-Mills theory, I review the contribution to its understanding by my collaborators and me. Contents: 1.Gauge Theories and Quantum Anomalies; 2.Mathematical Connections; 3. Gauge Field Dynamics other than Yang-Mills; 4. Gauge Formalism for General Relativity Variables; A. Christoffel connection as a gauge potential, B. Gravit

C. Iacobaeus, T. Francke, M. Danielsson, J. Ostling

We have studied gain vs. voltage characteristics and position resolutions of multistep capillary plates (two or three capillary plates operating in a cascade), as well as capillary plates operating in a mode when the main amplification occurs between plates or between the capillary plate and the readout plate (parallel plate amplification mode). Results of t

Rudolph C. Hwa, C. B. Yang

All hadronization processes, including fragmentation, are shown to proceed through recombination. The shower partons in a jet turn out to play an important role in describing the p_T spectra of hadrons produced in heavy-ion collisions. Due to the recombination of the shower partons with the soft thermal partons, the structure of jets produced in AA collision

B. El-Bennich, W. M. Kloet

We present a new fit to the LEAR data on antiproton-proton -> pi^- pi^+ differential cross sections and analyzing powers motivated by relativistic considerations. Within a quark model describing this annihilation we argue, since the pions are highly energetic, that relativistic effects cannot be neglected. The intrinsic pion wave functions are Lorentz transf

M. S. Hussein, L. F. Canto, R. Donangelo

The semiclassical method of Alder and Winther is generalized to study fusion reactions. As an illustration, we evaluate the fusion cross section in a schematic two-channel calculation. The results are shown to be in good agreement with those obtained with a quantal Coupled-Channels calculation. We suggest that in the case of coupling to continuum states this

Francesco Pederiva, A. Sarsa, K. E. Schmidt, S. Fantoni

The Auxiliary Field Diffusion Monte Carlo method has been applied to simulate droplets of 7 and 8 neutrons. Results for realistic nucleon-nucleon interactions, which include tensor, spin--orbit and three--body forces, plus a standard one--body confining potential, have been compared with analogous calculations obtained with Green&#39;s Function Monte Carlo m

Gennady Filippov, Yuliya Lashko

Role of the Pauli principle in the formation of both the discrete spectrum and multi-channel states of the binary nuclear systems composed of clusters is studied in the Algebraic Version of the resonating-group method. Solutions of the Hill-Wheeler equations in the discrete representation of a complete basis of the Pauli-allowed states are discussed for 4He+

P. A. Zolnierczuk, D. S. Armstrong, E. Christy, J. H. D. Clark

We report a search for low-lying exotic baryons via double radiative capture on pionic hydrogen. The data were collected at the TRIUMF cyclotron using the RMC spectrometer by detecting gamma-ray pairs from pion stops in liquid hydrogen. No evidence was found to support an earlier claim for exotic baryons of masses 1004 and 1044 MeV/$c^2$. We obtain upper lim

D. Albers, F. Bauer, J. Bisplinghoff, R. Bollmann

We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range $30 \leq θ_{c.m.} \leq 90$ deg. Details of the apparatus and the da

H. Rohdjess, D. Albers, J. Bisplinghoff, R. Bollmann

Thin polypropylene (CH$_2$) fibers have been used for internal experiments in storage rings as an option for hydrogen targets. The change of the hydrogen content due to the radiation dose applied by the circulating proton beam has been investigated in the range $1\cdot10^6$ to $2\cdot10^8$~Gy at beam momenta of 1.5 to 3 GeV/c by comparing the elastic pp-scat

H. Rohdjess, D. Albers, J. Bisplinghoff, R. Bollmann

The EDDA-Detector at the Cooler-Synchrotron COSY/Jülich has been operated with an internal CH$_2$ fiber target to measure proton-proton elastic scattering differential cross sections. For the data analysis knowledge of beam parameters, like position, width and angle, are indispensable. We have developed a method to obtain these values with high precision fro

A. Kisiel

STAR has performed a correlation analyses of pion-kaon and pion-proton pairs for sqrt(s_NN)=130 AGeV and sqrt(s_NN)=200 AGeV and kaon-proton, proton-Lambda and pion-Cascade pairs for AuAu collisions sqrt(s_NN)=200 AGeV. They show that average emission space-time points of pions, kaons and protons are not the same. These asymmetries are interpreted as a conse

T. Skrypnyk

Using special quasigraded Lie algebras we obtain new hierarchies of integrable nonlinear vector equations admitting zero-curvature representations. Among them the most interesting is extension of the generalized Landau-Lifshitz hierarchy which we call &#34;doubled&#34; generalized Landau-Lifshiz hierarchy. This hierarchy can be also interpreted as an anisotr