January 1998 arXiv papers — page 3

Shin'ichi Nojiri, Sergei D. Odintsov

The action for 2d dilatonic supergravity with dilaton coupled matter and dilaton multiplets is constructed. Trace anomaly and anomaly induced effective action (in components as well as in supersymmetric form) for matter supermultiplet on bosonic background are found. The one-loop effective action and large-$N$ effective action for quantum dilatonic supergrav

R. Arnowitt, Pran nath

Future sattelite (MAP and Planck) balloon and ground based experiments will the determine the basic cosmological parameters within a few percent. We examine here the effect of this on constraining the SUSY parameter space for supergravity R-parity conserving models (with tanbeta < 25) for the cases of nuCDM and LambdaCDM cosmological models. For the nuCDM (L

S. M. H. Wong

We report on a new equilibration scenario in relativistic heavy ion collisions, the scenario of the Increasingly Strongly Interacting Parton Plasma, and the effects of this scenario on equilibration and open charm, photon and dilepton production. The parton plasma is shown to be a very special kind of many-body system, which contains new physics concerning t

G. Battistoni, P. Lipari, J. Ranft, E. Scapparone

The effects of nuclear re-interactions in quasi elastic and resonant neutrino interactions have been considered in the framework of the nuclear models of the DPMJET code. A preliminary investigation on the modifications induced on the final state has been performed. Some consequences affecting the experimental identification are discussed.

S. Kumano

We discuss our studies of polarized parton distributions which are related to the RHIC-Spin project. First, the parametrization of unpolarized parton distributions is explained as an introduction to general audience. Second, activities of the RHIC-Spin-J working group are reported. In particular, preliminary results are shown on the parametrization of polari

M. Yoshimura

We discuss decay of unstable particles and pair annihilation of stable heavy particles that occur in the cosmic medium, from the point of the fundamental microscopic theory. A fully quantum mechanical treatment shows that the effect of thermal environment on these processes cannot be described in terms of quantities on the mass shell alone, thus requiring an

Jens Erler, Paul Langacker

We review the status of precision electroweak physics with particular emphasis on the extraction of the Higgs boson mass. Global fit results depend strongly on the used value for the hadronic contribution to alpha(M_Z). We emphasize, however, that the general tendency for a light Higgs persists when using any of the recently obtained values for alpha(M_Z), a

D0 Collaboration, B. Abbott et al

We have searched for the flavor-changing neutral current decay b -> s mu+ mu- in p pbar collisions at sqrt(s) = 1.8 TeV with the DO detector at Fermilab. We determine the 90% confidence level limit for the branching fraction to be B(b -> X_s mu+ mu-) < 3.2 x 10^{-4}. We argue that this limit is more stringent than the best published limit on this decay rate.

G. Dautcourt

As is well-known, Newton&#39;s gravitational theory can be formulated as a four-dimensional space-time theory and follows as singular limit from Einstein&#39;s theory, if the velocity of light tends to the infinity. Here &#39;singular&#39; stands for the fact, that the limiting geometrical structure differs from a regular Riemannian space-time. Geometrically

G. F. R. Ellis, B. A. Bassett, P. K. Dunsby

We consider the changes which occur in cosmological distances due to the combined effects of some null geodesics passing through low-density regions while others pass through lensing-induced caustics. This combination of effects increases observed areas corresponding to a given solid angle even when averaged over large angular scales, through the additive ef

H. Feldmann, A. J. Guttmann, I, Jensen

We present and analyze low-temperature series and complex-temperature partition function zeros for the $q$-state Potts model with $q=4$ on the honeycomb lattice and $q=3,4$ on the triangular lattice. A discussion is given as to how the locations of the singularities obtained from the series analysis correlate with the complex-temperature phase boundary. Exte

Joel Koplik, Jayanth R. Banavar

When a mixture of two viscous liquids flows past a solid wall there is an ambiguity in the use of the no-slip boundary condition. It is not obvious whether the mass-averaged velocity, the volume-averaged velocity, the individual species velocities, all or none of the above, or none of the above should exhibit no-slip. Extensive molecular dynamics simulations

C. Burgess, J. Cline, A. Lutken

It has been proposed that the effective Hamiltonian describing high T_c superconductivity in cuprate materials has an approximate SO(5) symmetry relating the superconducting (SC) and antiferromagnetic (AF) phases of these systems. We show that robust consequences of this proposal are potentially large optical conductivities and Raman scattering rates in the

D. J. Singh, I. I. Mazin

Local spin density approximation calculations are used to elucidate electronic and magnetic properties of Heusler structure Fe_2VAl. The compound is found to be a low carrier density semimetal. The Fermi surface has small hole pockets derived from a triply degenerate Fe derived state at Gamma compensated by an V derived electron pocket at the X point. The id

I. I. Mazin, D. J. Singh

The weighted density approximation, its implementation and its application to ferroelectric materials is discussed. Calculations are presented for several perovskite oxides and related materials. In general the weighted density approximation is found to be superior to either the local density or generalized gradient approximation for the ground state. Electr

Klaus M. Frahm, Thomas Guhr, Axel M&#34;uller-Groeling

We consider the spectral statistics of the superposition of a random diagonal matrix and a GUE matrix. By means of two alternative superanalytic approaches, the coset method and the graded eigenvalue method, we derive the two-level correlation function $X_2(r)$ and the number variance $Σ^2(r)$. The graded eigenvalue approach leads to an expression for $X_2(r

Renato Vicente, Osame Kinouchi, Nestor Caticha

We review the application of Statistical Mechanics methods to the study of online learning of a drifting concept in the limit of large systems. The model where a feed-forward network learns from examples generated by a time dependent teacher of the same architecture is analyzed. The best possible generalization ability is determined exactly, through the use

Orestis Terzidis, Philippe Claudin, Jean-Philippe Bouchaud

We extend the model of surface granular flow proposed in \cite{bcre} to account for the effect of an external `wind&#39;, which acts as to dislodge particles from the static bed, such that a stationary state of flowing grains is reached. We discuss in detail how this mechanism can be described in a phenomenological way, and show that a flat bed is linearly u

A. Auerbach

Problems of strongly interacting electrons can be greatly simplified by reducing them to effective quantum spin models. The initial step is renormalization of the Hamiltonian into a lower energy subspace. The positive and negative U Hubbard models are explicitely transformed into the Heisenberg and -x-xz models respectively. Basic tools of quantum magnetism

Jean Laherrère, D. Sornette

To account quantitatively for many reported ``natural&#39;&#39; fat tail distributions in Nature and Economy, we propose the stretched exponential family as a complement to the often used power law distributions. It has many advantages, among which to be economical with only two adjustable parameters with clear physical interpretation. Furthermore, it derive

G. Gonnella, E. Orlandini, J. M. Yeomans

Lattice Boltzmann simulations are used to investigate spinodal decomposition in a two-dimensional binary fluid with equilibrium lamellar and droplet phases. We emphasise the importance of hydrodynamic flow to the phase separation kinetics. For mixtures slightly asymmetric in composition the fluid phase separates into bulk and lamellar phases with the lamella

C. Cabrillo, G. J. Cuello, P. Garcia-Fernandez, F. J. Bermejo

We explore, by means of inelastic neutron scattering, the extent of changes in dynamic correlations induced by thermal poling of vitreous $SiO_2$. The measured vibrational density of states shows an excess of modes in certain frequency regions as well as a narrowing of the 100 meV peak. These findings indicate that such alterations cannot be ascribed to the

Matteo Marsili, Sergei Maslov, Yi-Cheng Zhang

Comment to D.H. Zanette and S.C. Manrubia, Phys. Rev. Lett. 79, 523 (1997).

Matteo Marsili, Yi-Cheng Zhang

We present a general approach to explain the Zipf&#39;s law of city distribution. If the simplest interaction (pairwise) is assumed, individuals tend to form cities in agreement with the well-known statistics

Toru Sakai, Minoru Takahashi

The ground state magnetization curve around the critical magnetic field $H_c$ of quantum spin chains with the spin gap is investigated. We propose a size scaling method to estimate the critical exponent $δ$ defined as $m\sim |H-H_c|^{1/δ}$ from finite cluster calculation. The applications of the method to the S=1 antiferromagnetic chain and S=1/2 bond altern

Juhao Wu, A. Widom

Standard statistical thermodynamic views of temperature fluctuations predict a magnitude $(\sqrt{<(ΔT)^2>}/T)\approx\sqrt{(k_B/C)}$ for a system with heat capacity $C$. The extent to which low temperatures can be well defined is discussed for those systems which obey the thermodynamic third law in the form $\lim_{(T\to 0)}C=0$. Physical limits on the notion

Hsiu-Hau Lin, Leon Balents, Matthew P. A. Fisher

A perturbative renormalization group analysis of interacting electrons on a two-leg ladder reveals that at half-filling any weakly repulsive system scales onto an exactly soluble Gross-Neveu model with a hidden SO(8) symmetry. The half-filled ground state is a Mott insulator with short-range d-wave pair correlations. We extract the exact energies, degeneraci

T. Shanks, N. Metcalfe, R. Fong, H. J. McCracken

We compare the galaxy evolution models of Bruzual & Charlot (1993) with the faint galaxy count, size and colour data from the Hubble and Herschel Deep Fields (Metcalfe et al 1996). For qo=0.05, we find that models where the SFR increases exponentially out to z>2 are consistent with all of the observational data. For qo=0.5, such models require an extra popul

M. Coleman Miller

Gravitomagnetic precession near neutron stars and black holes has received much recent attention, particularly as a possible explanation of 15--60 Hz quasi-periodic brightness oscillations (QPOs) from accreting neutron stars in low-mass X-ray binaries, and of somewhat higher-frequency QPOs from accreting stellar-mass black holes. Previous analyses of this ph

Thomas W. Baumgarte, Stuart L. Shapiro

We study neutrino emission from the remnant of an inspiraling binary neutron star following coalescence. The mass of the merged remnant is likely to exceed the stability limit of a cold, rotating neutron star. However, the angular momentum of the remnant may also approach or even exceed the Kerr limit, J/M^2 = 1, so that total collapse may not be possible un

D. E. Trilling, W. Benz, T. Guillot, J. I. Lunine

Giant planets in circumstellar disks can migrate inward from their initial (formation) positions. Radial migration is caused by inward torques between the planet and the disk; by outward torques between the planet and the spinning star; and by outward torques due to Roche lobe overflow and consequent mass loss from the planet. We present self-consistent nume

Cristiano Porciani, Sabino Matarrese, Francesco Lucchin, Paolo Catelan

We present a stochastic approach to the spatial clustering of dark matter haloes in Lagrangian space. Our formalism is based on a local formulation of the `excursion set&#39; approach by Bond et al., which automatically accounts for the `cloud-in-cloud&#39; problem in the identification of bound systems. Our method allows to calculate correlation functions o

Jeremy Goodman, Eric S. Dickson

Circularization of late-type main-sequence binaries is usually attributed to turbulent convection, while that of early-type binaries is explained by resonant excitation of g modes. We show that the latter mechanism operates in solar-type stars also and is at least as effective as convection, despite inefficient damping of g modes in the radiative core. The m

A. C. Fabian, K. Iwasawa, A. Celotti, W. N. Brandt

The X-ray luminous quasar GB 1428+4217 at redshift 4.72 has been observed with ASCA. The observed 0.5-10 keV flux is 3.2E-12 erg/s/cm2. We report here on the intrinsic 4-57 keV X-ray spectrum, which is very flat (photon index of 1.29). We find no evidence for flux variability within the ASCA dataset or between it and ROSAT data. We show that the overall spec

C. Hagmann, D. Kinion, W. Stoeffl, K. van Bibber

We report the first results of a high-sensitivity (10^{-23} Watt) search for light halo axions through their conversion to microwave photons. At 90 percent confidence we exclude a KSVZ axion of mass 2.9 x 10^{-6} eV to 3.3 x 10^{-6} eV as the dark matter in the halo of our Galaxy.

P. D. Naselsky, D. I. Novikov

The distribution of the polarization of the Cosmic Microwave Background (CMB) in the sky is determined by the hypothesis of random Gaussian distribution of the primordial density perturbations. This hypotheses is well motivated by the inflationary cosmology. Therefore, the test of consistency of the statistical properties of the CMB polarization field with t

Ulrich Kolb

We apply the disc instability model for soft X-ray transients to identify system parameters along evolutionary sequences of black hole X-ray binaries (BHXBs) that are consistent with transient behaviour. In particular, we focus on the hitherto neglected group of BHXBs with intermediate-mass giant donor stars. These spend a significant fraction of their X-ray

P. Royer, J. -M. Vreux, J. Manfroid

We present here tests of a five-filter photometric system aimed at WR classification. In addition to the well-known easy separation between the WN and WC spectral types, these tests indicate interesting potentialities in the discrimination of subgroups among the WN and the WC which look well related to the classical subtypes. The proposed combinations of fil

David R. Soderblom, Jeremy R. King, Robert B. Hanson, Burton F. Jones

This paper examines the discrepancy between distances to nearby open clusters as determined by parallaxes from Hipparcos compared to traditional main sequence fitting. The biggest difference is seen for the Pleiades, and our hypothesis is that if the Hipparcos distance to the Pleiades is correct, then similar subluminous ZAMS stars should exist elsewhere, in

C. Terquem, J. C. B. Papaloizou, R. P. Nelson, D. N. C. Lin

We calculate the dynamical tides raised on a non-rotating solar-type star by a close stellar or planetary companion. Dissipation arising from a turbulent viscosity operating in the convection zone and radiative damping in the radiative core are considered. We compute the torque exerted on the star by a companion in circular orbit, and determine the potential

G. Gavazzi, B. Catinella, L. Carrasco, A. Boselli

We present integrated H alpha measurements obtained from imaging observations of 98 late-type galaxies, primarily selected in the Coma supercluster. These data, combined with H alpha photometry from the literature, include a magnitude selected sample of spiral (Sa to Irr) galaxies belonging to the &#34;Great Wall&#34; complete up to mp=15.4, thus composed of

Gertrud Contardo, Matthias Steinmetz, Uta Fritze-von Alvensleben

The photometric evolution of galaxies in a hierarchically clustering universe is investigated. The study is based on high resolution numerical simulations which include the effects of gas dynamics, shock heating, radiative cooling and a heuristic star formation scheme. The outcome of the simulations is convolved with photometric models which enables us to pr

A. Aragon-Salamanca, C. M. Baugh, G. Kauffmann

We analyse the K-band Hubble diagram for a sample of brightest cluster galaxies (BCGs) in the redshift range 0<z<1. In good agreement with earlier studies, we confirm that the scatter in the absolute magnitudes of the galaxies is small (0.3 magnitudes). The BCGs exhibit very little luminosity evolution in this redshift range: if q_0=0.0 we detect no luminosi

E. Battaner

In a previous article, we have proposed that the large scale structure network generated by large scale magnetic fields could consist of a network of octahedra only contacting at their vertexes. Assuming such a network could arise at different scales producing a fractal geometry, we study here its properties, and in particular how a sub-octahedron network ca

T. Tanimori, Y. Hayami, S. Kamei, S. A. Dazeley

This paper reports the first discovery of TeV gamma-ray emission from a supernova remnant made with the CANGAROO 3.8 m Telescope. TeV gamma rays were detected at the sky position and extension coincident with the north-east (NE) rim of shell-type Supernova remnant (SNR) SN1006 (Type Ia). SN1006 has been a most likely candidate for an extended TeV Gamma-ray s

J. M. Carquillat, A. Jorissen, S. Udry, N. Ginestet

Orbital elements are presented for the Tc-poor S stars HR 363 (= HD 7351) and HD 191226. With an orbital period of 4592 d (=12.6 y), HR 363 has the longest period known among S stars, and yet it is a strong X-ray source. Its X-ray flux is similar to that of HD 35155, an S star with one of the shortest orbital periods (640 d). This surprising result is put in

S. Udry, A. Jorissen, M. Mayor, S. Van Eck

This paper provides orbital parameters for 38 barium stars and 10 extrinsic S stars derived from a decade-long CORAVEL monitoring. Lower bounds on the orbital period (generally exceeding 10 y) have been obtained for 10 more systems. Mira S, SC and (Tc-poor) C stars have also been monitored and show intrinsic radial-velocity variations due to atmospheric phen

A. Jorissen, S. Van Eck, M. Mayor, S. Udry

The set of orbital elements available for chemically-peculiar red giant (PRG) stars has been considerably enlarged thanks to a decade-long CORAVEL radial-velocity monitoring of about 70 barium stars and 50 S stars. This paper presents a detailed analysis of the complete set of orbital parameters available for PRG stars; the individual data are given in three

S. Basilakos, M. Plionis

We have reanalyzed and compared the dipoles of the 1.2 Jy and 0.6 Jy (QDOT) IRAS galaxy samples. We find strong indications from both samples for (a) significant contributions to the gravitational field that shapes the Local Group motion from depths up to $\sim 170$ $h^{-1}$ Mpc and (b) a large-scale coherence of the dipole anisotropy, indications provided m

Noella L. D&#39;Cruz, Craig L. Sarazin, Jacques Dubau

As noted first by Sunyaev & Churazov (1984), the 3.071 mm hyperfine line from $^{57}Fe^{+23}$ might be observable in astrophysical plasmas. We assess the atomic processes which might contribute to the excitation of this line. We determine the intensity of the hyperfine line from an isothermal, coronal plasma in collisional ionization equilibrium and for a co

R. Sadat, A. Blanchard, B. Guiderdoni, J. Silk

We study how Type Ia/II supernova rates at various redshifts can be used to constrain the cosmic star formation rate (CSFR) history. We use a spectrophotometric model of galaxy evolution which provides a self-consistent description of global properties of local galaxies. We have chosen two CSFR histories, with and without dust extinction, both normalized in

Benjamin D. Wandelt

I compute the 3-D non-linear evolution of gas and dark matter fluids in the neighbourhood of cosmic string wakes which are formed at high redshift ($z\simeq 2240$) for a ``realistic&#39;&#39; scenario of wake formation. These wakes are the ones which stand out most prominently as cosmological sheets and are expected to play a dominant rôle in the cosmic stri

S. D. Berger, B. I. Halperin

Matveev and Larkin calculated the parity effect on the ground state energy of a small superconducting particle in the regimes where the mean level spacing is either large or small compared to the bulk gap. We perform a numerical calculation which extends their results into the intermediate regime, where the level spacing is of the same order as the bulk gap.

Jose F. Morales, Claudio A. Scrucca, Marco Serone

We study spin interactions between two moving D-branes using the Green-Schwarz formalism of boundary states. We focus our attention on the leading terms for small velocities v, of the form v^{4-n}/r^{7-p+n} (v^{2-n}/r^{3-p+n}) for p-p (p-p+4) systems, with 16 (8) supercharges. In analogy with standard G-S computations of massless four-point one-loop amplitud

A. W. C. Lau, P. Pincus

In this Letter, we consider a neutral system of mobile positive and negative charges confined on the surface of curved films. This may be an appropriate model for: i) a highly charged membrane whose counterions are confined to a sheath near its surface; ii) a membrane composed of an equimolar mixture of anionic and cationic surfactants in aqueous solution. W

Frank Wilczek

It is shown how a metric structure can be induced in a simple way starting with a gauge structure and a preferred volume, by spontaneous symmetry breaking. A polynomial action, including coupling to matter, is constructed for the symmetric phase. It is argued that assuming a preferred volume, in the context of a metric theory, induces only a limited modifica

D. Bolle, P. Kozlowski

An Ashkin-Teller neural network, allowing for two types of neurons is considered in the case of low loading as a function of the strength of the respective couplings between these neurons. The storage and retrieval of embedded patterns built from the two types of neurons, with different degrees of (in)dependence is studied. In particular, thermodynamic prope

B. Eynard, E. Guitter, C. Kristjansen

Consider a random three-coordinate lattice of spherical topology having 2v vertices and being densely covered by a single closed, self-avoiding walk, i.e. being equipped with a Hamiltonian cycle. We determine the number of such objects as a function of v. Furthermore we express the partition function of the corresponding statistical model as an elliptic inte

D. Yvon, V. Sushkov

We have developed preamplifier configurations used to readout resistive bolometers such as those based on Neutron Transmuted Doped Germanium thermometers (so called NTD Ge thermometers)[1] or NbSi thin film thermometers [2, 3]. We introduce the impedance regulating preamplifier configuration. This configuration, is compared to previously proposed readout con

Jean-Philippe Bouchaud, Rama Cont

We propose a non linear Langevin equation as a model for stock market fluctuations and crashes. This equation is based on an identification of the different processes influencing the demand and supply, and their mathematical transcription. We emphasize the importance of feedback effects of price variations onto themselves. Risk aversion, in particular, leads

L. A. Kondratyuk, A. Sibirtsev, W. Cassing, Ye. S. Golubeva

We calculate the momentum dependence of the $ρ$-meson selfenergy based on the dispersion relation for the $ρN$ scattering amplitude $f(ω$) at low nuclear density. The imaginary part of $f(ω)$ is determined from the optical theorem, while the total $ρN$ cross section is obtained within the VDM at high energy and within the resonance model at low energy. Our n

Masayuki Tanimoto

Gowdy spacetimes are generalized to admit two commuting spatial &#34;local&#34; Killing vectors, and some new varieties of them are presented, which are all closely related to Thurston&#39;s geometries. Explicit spatial compactifications, as well as the boundary conditions for the metrics are given in a systematic way. A short comment on an implication to th

Loran Ts. Adzhemyan, Nikolaj V. Antonov, Alexander N. Vasil&#39;ev

Field theoretical renormalization group methods are applied to the Obukhov--Kraichnan model of a passive scalar advected by the Gaussian velocity field with the covariance $<{\bf v}(t,{\bf x}){\bf v}(t&#39;,{\bf x})> - < v(t,{\bf x}){\bf v}(t&#39;,x&#39;)> \proptoδ(t-t&#39;)| x-x&#39;|^{\eps}$. Inertial range anomalous scaling for the structure functions and

H. Smolinski, C. Gros, W. Weber, U. Peuchert

A new X-ray diffraction study of the one-dimensional spin-Peierls compound α-NaV_2O_5 reveals a centrosymmetric (Pmmn) crystal structure with one type of V site, contrary to the previously postulated non-centrosymmetric P2_1mn structure with two types of V sites (V^{+4} and V^{+5}). Density functional calculations indicate that NaV_2O_5 is a quarter-filled l

Debashis Gangopadhyay, Soumitra Sengupta

We show that for a string moving in a background consisting of maximally symmetric gravity, dilaton field and second rank antisymmetric tensor field, the $O(d) \otimes O(d)$ transformation on the vacuum solutions gives inequivalent solutions that are not maximally symmetric. We then show that the usual physical meaning of maximal symmetry can be made to rema

A. Ali Khan, T. Bhattacharya, S. Collins, C. T. H. Davies

We present quenched results for B meson decay constants using NRQCD b quarks and O(a) tadpole improved clover light quarks. For the first time, one-loop matching factors between lattice and continuum currents are incorporated through O(\alpha/M) taking operator mixing fully into account. This includes an important O(\alpha a) discretization correction to the

B. R. Dawson, R. Meyhandan, K. M. Simpson

In recent years the Fly&#39;s Eye and Akeno groups have presented analyses of the cosmic ray mass composition at energies above 10^17 eV. While the analysis of the Fly&#39;s Eye group points to a likely change in mass composition from heavy to light at energies above 10^18 eV, the Akeno analysis favours an unchanging composition. However, the two groups base

A. Panaitescu, P. Meszaros, M. J. Rees

We present an analytical approach to calculate the hydrodynamics of the interaction between a relativistic ejecta and a surrounding medium, whose evolution serves as a model for Gamma-Ray Burst afterglows. We investigate the effect of the relevant model parameters on the X-ray, optical and radio fluxes, and the effect of a refreshed shock energy input and an

Jonathan Thornburg

When using the black hole exclusion (horizon boundary condition) technique, $K$ is usually nonzero and spatially variable, so none of the special cases of York&#39;s conformal-decomposition algorithm apply, and the full 4-vector nonlinear York equations must be solved numerically. We discuss the construction of dynamic black hole initial data slices using th

Steven R. White, D. J. Scalapino

Using the density matrix renormalization group, we calculate the energy of a domain wall in the 2D t-J model as a function of the linear hole density ρ_\ell, as well as the interaction energy between walls, for J/t=0.35. Based on these results, we conclude that the ground state always has domain walls for dopings 0 < x < 0.3. For x < 0.125, the system has (1

Masaru Watanabe, Takashi Ichikawa, Sadanori Okamura

We obtain an unbiased estimate of the global Hubble constant H0 in the volume of cz<12000km/s in the region of Pisces-Perseus. The Tully-Fisher (TF) relation is applied to a magnitude limited sample of 441 spirals selected from the Arecibo 21cm catalog. The photometry data were calibrated with CCD observations and we achieve 0.13mag for the photometric inter

G. N. Nugmanova

The Lakshmanan equivalent counterparts of the some Myrzakulov equations are found.

Giacomo M. D&#39;Ariano, Prem Kumar

We present a quantum-mechanical analysis of a nonlinear interferometer that achieves optical switching via cross-phase modulation resulting from the Kerr effect. We show how it performs as a very precise optical regenerator, highly improving the transmitted bit-error rate in the presence of loss.

Vladimir S. Mashkevich

We argue that the claim given in quant-ph/9801014 is untenable. The fallacy in the proof is a misinterpretation of the no-cloning theorem, which does not allow quantum jumps, specifically measurements.

Thierry Gallay, Alexander Mielke

For the time-dependent Ginzburg-Landau equation on the real line, we construct solutions which converge, as $x \to \pm\infty$, to periodic stationary states with different wave-numbers $η_\pm$. These solutions are stable with respect to small perturbations, and approach as $t \to +\infty$ a universal diffusive profile depending only on the values of $η_\pm$.

Peter Filip

It is shown that azimuthal asymmetry in transverse momentum distribution of particles observed in non-central heavy ion collisions can originate from pre-equilibrium rescattering. The phenomenon is studied using computer simulation of expanding pion gas created in Pb+Pb 160 GeV/n collisions. Results obtained are discussed in comparison with experimental resu

A. I. L&#39;vov, R. L. Workman

Compton scattering data are sensitive to the existence of low-mass resonances reported by Tatischeff et al. We show that such states, with their reported properties, are excluded by previous Compton scattering experiments.

J. Dobaczewski

We present a very brief description of the Hartree-Fock method in nuclear structure physics, discuss the numerical methods used to solve the self-consistent equations, and analyze the precision and convergence properties of solutions. As an application we present results pertaining to quadrupole moments and single-particle quadrupole polarizations in superde

Alan H. Durfee

This article recounts the interaction of topology and singularity theory (mainly singularities of complex algebraic varieties) which started in the early part of this century and bloomed in the 1960&#39;s with the work of Hirzebruch, Brieskorn, Milnor and others. Some of the topics are followed to the present day. (A chapter for the book &#34;History of Topo

P. B. A. Lecomte

One computes the cohomology of the projective embedding of sl(m+1,R) acting on the differential operators on densities on R^m of various weights. This cohomology is non vanishing only for some special critical values of the weights. This allows us first to explain some strange feature pointed out by Gargoubi in his classification if the module of differentia

C. McA. Gordon, J. Luecke

Let M be a simple 3-manifold with a toral boundary component partial_0 M. If Dehn filling M along partial_0 M one way produces a toroidal manifold and Dehn filling M along partial_0 M another way produces a boundary-reducible manifold, then we show that the absolute value of the intersection number on partial_0 M of the two filling slopes is at most two. In

G. Leibbrandt, A. Richardson, C. P. Martin

The complete UV-divergent contribution to the one-loop 1PI four-point function of Yang-Mills theory in the light-cone gauge is computed in this paper. The formidable UV-divergent contributions arising from each four-point Feynman diagram yield a succinct final result which contains nonlocal terms as expected. These nonlocal contributions are consistent with

Jnanadeva Maharana

A worldvolume action for membrane is considered to study the target space local symmetries. We introduce a set of generators of canonical transformations to exhibit the target space symmetries such as the general coordinate transformation and the gauge transformation of antisymmetric tensor field. Similar results are derived for type IIB string with manifest

A. Losev

The &#34;Hodge strings&#34; construction of solutions to associativity equations is proposed. From the topological string theory point of view this construction formalizes the &#34;integration over the position of the marked point&#34; procedure for computation of amplitudes. From the mathematical point of view the &#34;Hodge strings&#34; construction is jus

P. D. Jarvis, J. W. van Holten, J. Kowalski-Glikman

The spinorial local world-line $κ$-symmetry of the covariant Brink-Schwarz formulation of the 4-$D$ superparticle is abelian in an off-shell phase-space formulation. The result is shown to generalize to the extended spinorial transformations of the spinning superparticle.

Alexander Burinskii, Giulio Magli

Behaviour of singularities of the rotating black holes under an arbitrary boost is considered on the basis of a complex representation of the Kerr theorem. We give a simple algorithm allowing to get explicit expressions for the metric and the position of the singularities for arbitrary direction and magnitude of the boost, including the ultrarelativistic cas

A. A. Deriglazov, D. M. Gitman

It is shown that recently pointed out by Berkovits on-shell degrees of freedom of the D=11 superstring do not make contributions into the quantum states spectrum of the theory. As a consequence, the spectrum coincides with that of the D=10 type IIA superstring.

Dae Sung Hwang, Bum-Hoon Lee

We calculate the form factors of $B\toπ$ and $B\toρ$ heavy to light transition matrix elements by using the factorization formalism of perturbative QCD. We obtain them at $q^2=0$ and show their dependences on the parameter $ε$ of the B meson distribution amplitude. We also obtain the form factors as functions of $q^2$ in the region $0\le q^2 \le M_B^2/2$. Th

M. Ciuchini, R. Contino, E. Franco, G. Martinelli

We discuss few selected topics related to the calculation of hadronic amplitudes relevant for two-body non-leptonic B decays.

M. Jezabek, J. H. Kuhn, M. Peter, Y. Sumino

We include the full second-order corrections to the static QCD potential in the analysis of the ttbar threshold cross section. Then we examine the difference between the results obtained in the momentum-space approach and in the coordinate-space approach, which was found recently. Contrary to our expectation, the reduction of the difference by the inclusion

Johan Bijnens, Peter Gosdzinsky, Pere Talavera

We calculate the leading quark mass corrections of order $m_q\log(m_q)$, $m_q$ and $m_q^{3/2}$ to the vector meson decay constants within Heavy Vector Meson Chiral Perturbation Theory. We discuss the issue of electromagnetic gauge invariance and the heavy mass expansion. Reasonably good fits to the observed decay constants are obtained.

John F. Gunion

A review of supersymmetry theory and phenomenology is presented. Topics discussed include: gravity-mediated (SUGRA) and gauge-mediated (GMSB) supersymmetry breaking models; an overview of non-universal soft-supersymmetry-breaking masses and the resulting experimental implications; the phenomenology of and constraints on the possibility that a massive gluino

C. Bernard, T. Blum, A. Soni

Results in the quenched approximation for SU(3) breaking ratios of the heavy-light decay constants and the $ΔF=2$ mixing matrix elements are reported. Using lattice simulations at $6/g^2=5.7$, 5.85, 6.0, and 6.3, we directly compute the mixing matrix element $M_{hl}=< \bar P_{hl}|\bar h γ_μ(1-γ_5)l \bar h γ_μ(1-γ_5)l|P_{hl}>$. Extrapolating to the physical B

T. DeGrand, Anna Hasenfratz, Tamas Kovacs

This talk is a review of our studies of instantons and their properties as seen in our lattice simulations of SU(2) gauge theory. We have measured the topological susceptibility and the size distribution of instantons in the QCD vacuum. We have also investigated the properties of quarks moving in instanton background field configurations, where the sizes and

The OPAL Collaboration, K. Ackerstaff et al

A search for decays of the B_c meson was performed using data collected from 1990-1995 with the OPAL detector on or near the Z peak at LEP. The decay channels B_c^+ -> J/psi pi^+, B_c^+ -> J/psi a_1^+ and B_c^+ -> J/psi ell^+ nu were investigated, where ell denotes an electron or a muon. Two candidates are observed in the mode B_c^+ -> J/psi pi^+, with an es

D0 Collaboration, B. Abbott

We determine the top quark mass m_t using t-tbar pairs produced in the D0 detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar W^- final states with one W boson decaying to q-qbar and the other to e-nu or mu-nu. Likelihood fits to the data yield m_t(l+jet

Cristian Martinez

The three dimensional black hole solution of Einstein equations with negative cosmological constant coupled to a conformal scalar field is proved to be unstable against linear circularly symmetric perturbations.

James E. Lidsey, J. Maharana

A supersymmetric approach to string quantum cosmology based on the non-compact, global duality symmetries of the effective action is developed. An N=2 supersymmetric action is derived whose bosonic component is the Neveu-Schwarz/Neveu-Schwarz sector of the $(d+1)$--dimensional effective action compactified on a $d$--torus. A representation for the supercharg

Jacek Gruszczak

Differential properties of a spin 2 boson field $ψ_{μν}$ describing propagation of gravitational perturbations on a straight cosmic string&#39;s space-time background are studied by means of methods of the differential spaces theory. It is shown that this field is a smooth one in the interior of cosmic string&#39;s space-time and looses this property at the

Naomichi Hatano

A recent development in studies of random non-Hermitian quantum systems is reviewed. Delocalization was found to occur under a sufficiently large constant imaginary vector potential even in one and two dimensions. The phenomenon has a physical realization as flux-line depinning in type-II superconductors. Relations between the delocalization transition and t