September 1999 arXiv papers — page 4

Serge F. Mingaleev, Yuri B. Gaididei, Eva Majernikova, Serge Shpyrko

We study effects of Kac-Baker long-range dispersive interaction (LRI) between particles on kink properties in the discrete sine-Gordon model. We show that the kink width increases indefinitely as the range of LRI grows only in the case of strong interparticle coupling. On the contrary, the kink becomes intrinsically localized if the coupling is under some cr

A. C. C. Coolen, D. Saad

We study the dynamics of supervised learning in layered neural networks, in the regime where the size $p$ of the training set is proportional to the number $N$ of inputs. Here the local fields are no longer described by Gaussian probability distributions and the learning dynamics is of a spin-glass nature, with the composition of the training set playing the

Herbert Schoeller

This article presents a tutorial introduction to a recently developed real-time renormalization group method. It describes nonequilibrium properties of discrete quantum systems coupled linearly to an environment. We illustrate the technique by a simple and exactly solvable model: A quantum dot consisting of a single non-degenerate level coupled to two reserv

J. A. Reedijk, H. C. F. Martens, H. B. Brom, M. A. J. Michels

The interplay between inter- and intra-chain charge transport in bulk polythiophene in the hopping regime has been clarified by studying the conductivity as a function of frequency (up to 3 THz), temperature and doping level. We present a model which quantitatively explains the observed crossover from quasi-one-dimensional transport to three-dimensional hopp

B. von Haeften, R. Deza, H. S. Wio

Recent massive numerical simulations have shown that the response of a "stochastic resonator" is enhanced as a consequence of spatial coupling. Similar results have been analytically obtained in a reaction-diffusion model, using "nonequilibrium potential" techniques. We now consider a field-dependent diffusivity and show that the "selecti

Andrew Matacz, Jean-Philippe Bouchaud

We present compelling empirical evidence for a new interpretation of the Forward Rate Curve (FRC) term structure. We find that the average FRC follows a square-root law, with a prefactor related to the spot volatility, suggesting a Value-at-Risk like pricing. We find a striking correlation between the instantaneous FRC and the past spot trend over a certain

E. Orlandini, F. Seno, A. L. Stella

A linear copolymer made of two reciprocally attracting N-monomer blocks collapses to a compact phase through a novel transition, whose exponents are determined with extensive MC simulations in two and three dimensions. In the former case, an identification with the statistical geometry of suitable percolation paths allows to predict that the number of contac

T. Omiya, F. Matsukura, T. Dietl, Y. Ohno

Magnetotransport properties of ferromagnetic semiconductor (Ga,Mn)As have been investigated. Measurements at low temperature (50 mK) and high magnetic field (<= 27 T) have been employed in order to determine the hole concentration p = 3.5x10^20 cm ^-3 of a metallic (Ga0.947Mn0.053)As layer. The analysis of the temperature and magnetic field dependencies of t

Seung-Yeon Kim, Richard J. Creswick

The Yang-Lee zeros of the Q-state Potts model are investigated in 1, 2 and 3 dimensions. Analytical results derived from the transfer matrix for the one-dimensional model reveal a systematic behavior of the locus of zeros as a function of Q. For 1<Q<2 the zeros in the complex $x=\exp(βH_q)$ plane lie inside the unit circle, while for Q>2 they lie outside the

Seung-Yeon Kim, Richard J. Creswick, Chi-Ning Chen, Chin-Kun Hu

The distribution of the zeros of the partition function in the complex temperature plane (Fisher zeros) of the two-dimensional Q-state Potts model is studied for non-integer Q. On $L\times L$ self-dual lattices studied ($L\le8$), no Fisher zero lies on the unit circle $p_0=e^{iθ}$ in the complex $p=(e^{βJ}-1)/\sqrt{Q}$ plane for Q<1, while some of the Fisher

Richard J. Creswick, Seung-Yeon Kim

The microcanonical transfer matrix and its extensions offer a new way of obtaining exact partition functions on finite two dimensional lattices. We show the density of the partition function zeros in the complex x- plane for the Ising model at $y=y_c$ and $y=0.5y_c$, and the density of the partition function zeros in the complex y-plane for the three-state P

Ramandeep S. Johal

It is argued that polydispersed systems like colloids provide a direct example where Tsallis&#39; statistical distribution is useful for describing the heirarchical nature of the system based on particle size.

A. E. Piatti, D. Geisler, E. Bica, J. J. Claria

We present Washington C, T1 CCD photometry of 21 fields located in the northern part of the Large Magellanic Cloud (LMC), and spread over a region of more than 2.52 degrees approximately 6 degrees from the bar. The surveyed areas were chosen on the basis of their proximity to SL 388 and SL 509, whose fields showed the presence of a secondary giant clump, obs

N. J. Jackson, E. Xanthopoulos, I. W. A. Browne

We present Hubble Space Telescope (HST) infrared images of four gravitational lens systems from the JVAS/CLASS gravitational lens survey and compare the new infrared HST pictures with previously published WFPC2 HST optical images and radio maps. Apart from the wealth of information that we get from the flux ratios and accurate positions and separations of th

Osorio Mayra, Lizano Susana, D&#39;Alessio Paola

It has been proposed that some hot molecular cores (HMCs) harbor a young embedded massive star, which heats an infalling envelope and accretes mass at a rate high enough to ``choke off&#39;&#39; an incipient HII region. This class of HMCs would mark the youngest phase known of massive star formation. In order to test this hypothesis, we model this type of ob

Stefan W. Dieters, Michiel van der Klis

We present a systematic, homogeneous analysis of all the EXOSAT ME, high time resolution data on Sco X-1. We investigate all power spectral properties of the $<$100 Hz quasi-periodic oscillations (QPO) and noise of Sco X-1 as a function of position on the Z-shaped track traced out in the X-ray colour-colour diagram. Generally, the properties of Sco X-1 vary

Judith G. Cohen

Radial velocities are presented for a new sample of globular clusters in the outer halo of M87 at a distance of 300 to 540 arcsec (24 to 43 kpc) from the center of this galaxy. These are used to augment our previously published data and an analysis of the rotation and velocity dispersion of the M87 globular cluster system is carried out. The rotation is $\si

Allen V. Sweigart

We have investigated the possibility that radiation pressure might trigger planetary nebula (PN) ejection during helium-shell flashes in asymptotic- giant-branch (AGB) stars. We find that the outward flux at the base of the hydrogen envelope during a flash will reach the Eddington limit when the envelope mass falls below a critical value that depends on the

Simon P. Driver

From the Hubble Deep Field catalog presented in Driver et al. (1998) we derive the local (0.3 < z < 0.5) Bivariate Brightness Distribution (BBD) of field galaxies within a 326 Mpc**3 Volume-Limited sample. The sample contains 47 galaxies which uniformally sample the underlying galaxy population within the specified redshift, magnitude and surface brightness

H. Monteiro, C. Morisset, R. Gruenwald, S. M. Viegas

We present a new modeling tool for planetary nebulae (PNe), based on 3D photoionization calculations. From models for two theoretical PNe, we show that the enhancement in the equatorial zone observed in several PNe is not necessarily due to a density gradient, as usually interpreted. We study the morpho-kinematic properties of the PN NGC 3132 and show that a

D. A. White

In Paper-I we presented a methodology to recover the spatial variations of properties of the intracluster gas from ASCA X-ray satellite observations of galaxy clusters. We verified the correctness of this procedure by applying it to simulated cluster datasets which we had subjected to the various contaminants common in ASCA data. In this paper we present the

Paul L. Schechter

The author reports his recollections of what transpired. These may or may not prove consistent with the contributions to be published in the proceedings. Corrections are welcome.

M. Feroci, G. Matt, G. Pooley, E. Costa

Simultaneous X-ray (BeppoSAX, 0.1-300 keV) and radio (Ryle Telescope, 15 GHz) observations of the superluminal galactic source GRS 1915+105 in high flux state were carried out starting October 1996. Here we present the simultaneous radio/X-ray light curves of the flare event and the spectral and timing analysis of the relevant BeppoSAX data. We obtain eviden

R. Nufer, W. Baltensperger, W. Woelfli

For a hypothetical planet on a highly eccentric orbit, we have calculated the osculating orbital parameters and its closest approaches to Earth and Moon over a period of 750 kyr. The approaches which are close enough to influence the climate of the Earth form a pattern comparable to that of the past climatic changes, as recorded in deep sea sediments and pol

S. Sabatini, R. Scaramella, V. Testa, S. Andreon

Low Surface Brightness Galaxies (LSBGs) today constitute the less known fraction of galaxies: their number density and their physical properties (e.g. luminosity, colour, dynamics) are still largely uncertain. This is mainly due to the difficoulty in finding them (since their presence goes often unnoticed when astronomical images are analyzed with standard m

V. De Bruyne, F. Leeuwin, H. Dejonghe

We use a set of Stackel potentials to obtain a local approximation for an effective third integral in axisymmetric systems. We present a study on the feasibility and effectiveness of this approach. We have applied it to three trial potentials of various flattenings, corresponding to nearly ellipsoidal, disky and boxy density isophotes. In all three cases, a

M. Reyniers, H. Van Winckel

The observational data guiding the theoretical chemical evolutionary models of AGB stars come mainly from the analysis of intrinsic and extrinsic s-process enriched objects. The first are the stars of the M-MS-S-SC-C star sequence which is thought to reflect, at least partly, the evolution on the AGB of a single star towards an increasing C/O ratio. The seco

E. Xanthopoulos, I. W. A. Browne, P. N. Wilkinson, N. J. Jackson

We present an overview of all the observations (radio - VLA, MERLIN, VLBA,EVN - and optical - WFPC2 and NICMOS -) that were initially used to confirm the gravitational lens nature of the double JVAS system B1030+074. Since the 1.56 arcsec system showed some first indication of variability it has been monitored with the VLA and MERLIN to confirm its variable

I. W. A. Browne, E. Xanthopoulos, A. D. Biggs, M. Norbury

The complex 10-component gravitational lens B1933+503 has been monitored with the VLA during the period February to June 1998. Here we present the results of this A-configuration 8.4 GHz monitoring campaign. The 37 epochs of observations have an average spacing of 3 days. The data have yielded light curves for the four flat-spectrum radio components (compone

S. Pellegrini

Hubble Space Telescope observations revealed that the central surface brightness profiles of early type galaxies can be divided into two types: &#34;core&#34; profiles and featureless power law profiles. On the basis of this and previous results, early type galaxies have been grouped into two families: coreless galaxies, which are also rapidly rotating, near

D. A. White, D. Buote

In this paper we describe a self-contained method for performing the spectral-imaging deconvolution of X-ray data on clusters of galaxies observed by the ASCA satellite. Spatially-resolved spectral studies of data from this satellite require such a correction because its optics redistribute photons over regions which are of comparable size to the angular sca

David McDavid

New observations of 9 of the brightest northern O stars have been made with the Breger polarimeter on the 0.9~m telescope at McDonald Observatory and the AnyPol polarimeter on the 0.4~m telescope at Limber Observatory, using the Johnson-Cousins UBVRI broadband filter system. Comparison with earlier measurements shows no clearly defined long-term polarization

D. N. McKinsey, J. M. Doyle

The use of liquid helium and neon as scintillators for neutrino detection is investigated. Several unique properties of these cryogens make them promising candidates for real-time solar neutrino spectroscopy: large ultraviolet scintillation yields from ionizing radiation, transparency to their own scintillation light, and low levels of radioactive impurities

Alexei Kiselev

The supersymmetry self-consistent approximation for the model of non-equilibrium thermodynamic system with quenched disorder is derived from the dynamical action calculated by means of generalized second Legendre transformation. The equations for adiabatic and isothermal susceptibilities, memory and field induced parameters are obtained on the basis of asymp

E. Lima, H. Lu, B. A. Ovrut, C. N. Pope

We obtain new solutions where a string and a pp-wave lie in the common worldvolume directions of the non-standard intersection of two gauge 5-branes in the heterotic string. The two 5-branes are supported by independent SU(2) Yang-Mills instantons in their respective (non-overlapping) transverse spaces. We present a detailed study of the unbroken supersymmet

Stefano Bellucci, Anton Galajinsky

We reconsider the problem of BRST quantization of a mechanics with infinitely reducible first class constraints. Following an earlier recipe [Phys. Lett. B 381, 105, (1996)], the original phase space is extended by purely auxiliary variables, the constraint set in the enlarged space being first stage of reducibility. The BRST charge involving only a finite n

D. L. Hornidge, B. J. Warkentin, R. Igarashi, J. C. Bergstrom

Cross sections for elastic Compton scattering from the deuteron were measured over the laboratory angles 35-150 deg. Tagged photons in the laboratory energy range 84-105 MeV were scattered from liquid deuterium and detected in the large-volume Boston University NaI (BUNI) spectrometer. Using the calculations of Levchuk and L&#39;vov, along with the measured

C. Adam, B. Muratori, C. Nash

We study an Abelian Chern-Simons and Fermion system in three dimensions. In the presence of a fixed prescribed background magnetic field we find an infinite number of fully three-dimensional solutions. These solutions are related to Hopf maps and are, therefore, labelled by the Hopf index. Further we discuss the interpretation of the background field.

Gary Felder, Lev Kofman, Andrei Linde

A theory of gravitational production of light scalar particles during and after inflation is investigated. We show that in the most interesting cases where long-wavelength fluctuations of light scalar fields can be generated during inflation, these fluctuations rather than quantum fluctuations produced after inflation give the dominant contribution to partic

S. Blum, U. Kraus

We report on our analysis of a large sample of energy dependent pulse profiles of the X-ray binary pulsar Hercules X-1. We find that all data are compatible with the assumption of a slightly distorted magnetic dipole field as sole cause of the asymmetry of the observed pulse profiles. Further the analysis provides evidence that the emission from both poles i

J. Kent Harbaugh, D. Stroud

We describe a simple Hamiltonian for an underdamped Josephson array coupled to a single photon mode in a resonant cavity. Using a Hartree-like mean-field theory, we show that, for any given strength of coupling between the photon field and the Josephson junctions, there is a transition from incoherence to coherence as a function of N, the number of Josephson

E. Mandonnet, A. Minguzi, R. Dum, I. Carusotto

We present a theoretical analysis of the evaporative cooling of an atomic beam propagating in a magnetic guide. Cooling is provided by transverse evaporation. The atomic dynamics inside the guide is analyzed by solving the Boltzmann equation with two different approaches: an approximate analytical ansatz and a Monte-Carlo simulation. Within their domain of v

K. Jedamzik

I consider the synthesis of 6Li due to the decay of relic particles, such as gravitinos or moduli, after the epoch of Big Bang Nucleosynthesis. The synthesized 6Li/H ratio may be compared to 6Li/H in metal-poor stars which, in the absence of stellar depletion of 6Li, yields significantly stronger constraints on relic particle densities than the usual conside

Axel Krause

We analyse perturbatively, whether a flat background with vanishing G-flux in Horava-Witten supergravity represents a vacuum state, which is stable with respect to interactions between the ten-dimensional boundaries, mediated through the D=11 supergravity bulk fields. For this, we consider fluctuations in the graviton, gravitino and 3-form around the flat ba

Uma Mahanta

In this paper we show that the mixing between leptoquarks (LQ&#39;s) from different $SU(2)_l$ multiplets can generate a non-trivial Majorana mass matrix for neutrinos through one loop self energy diagrams. Such mixing can arise from gauge invariant and renormalizable LQ-Higgs interaction terms after EW symmetry breaking. We use the experimental indication on

Pedro J. de A. Bicudo

We address the problem of the fermion species doubling on the Lattice. Our strategy is to factorize the fermion doubles from the action. The mass term of the Dirac-Wilson action is changed. In this case the extra roots which appear in the action of free fermions in the moment representation are independent of the mass and can be factorized from the fermion p

J. Troost

We analyse field strength configurations in U(N) Yang-Mills theory on T^{2n} that are diagonal and constant, extending early work of Van Baal on T^4. The spectrum of fluctuations is determined and the eigenfunctions are given explicitly in terms of theta functions on tori. We show the relevance of the analysis to higher dimensional D-branes and discuss appli

Zhi-zhong Xing

I propose a simple extension of the bi-maximal neutrino mixing pattern, allowing slight coupling between solar and atmospheric neutrino oscillations as well as large CP violation. The new scenario is compatible with either the vacuum oscillation solution or the large-angle MSW solution to the solar neutrino

Vesselin Petkov

It is shown that the complete description of the propagation of light in a gravitational field and in non-inertial reference frames in general requires an average coordinate and an average proper velocity of light. The need for an average coordinate velocity of light in non-inertial frames is demonstrated by considering the propagation of two vertical light

V. Hushwater

We study the Casimir force between a perfectly conducting and an infinitely permeable plate with the radiation pressure approach. This method illustrates how a repulsive force arises as a consequence of the redistribution of the vacuum-field modes corresponding to specific boundary conditions. We discuss also how the method of the zero-point radiation pressu

P. G. Kwiat, A. G. White, J. R. Mitchell, O. Nairz

The phenomenon of quantum interrogation allows one to optically detect the presence of an absorbing object, without the measuring light interacting with it. In an application of the quantum Zeno effect, the object inhibits the otherwise coherent evolution of the light, such that the probability that an interrogating photon is absorbed can in principle be arb

Apoorva Patel

Quantum computation is a rapidly progressing field today. What are its principles? In what sense is it distinct from conventional computation? What are its advantages and disadvantages? What type of problems can it address? How practical is it to make a quantum computer? I summarise some of the important concepts of quantum computation, in an attempt to answ

A. Bohm, H. Kaldass

The Rigged Hilbert Space (RHS) theory of resonance scattering and decay is reviewed and contrasted with the standard Hilbert space (HS) theory of quantum mechanics. The main difference is in the choice of boundary conditions. Whereas the conventional theory allows for the in-states $ϕ^+$ and the out-states (observables) $ψ^-$ of the S-matrix elements $(ψ^-,ϕ

G. Odor, A. Krikelis, F. Vesztergombi, F. Rohrbach

We show that the latest version of massively parallel processing associative string processing architecture (System-V) is applicable for fast Monte Carlo simulation if an effective on-processor random number generator is implemented. Our lagged Fibonacci generator can produce $10^8$ random numbers on a processor string of 12K PE-s. The time dependent Monte C

Hiroki Nakamura, Ryoichi Seki

We investigate a domain-structured source in the pion interferometry of relativistic nuclear collisions. The source emits coherent pions intermittently with the background of chaotic pions. The coherent pions examined are either of a general nature or of disoriented chiral condensate. Two- and three-pion correlations for the source are shown to agree well wi

Steven P. Wells, Scott W. Wissink

Using data obtained through simultaneous measurements of (p,p&#39;) spin-transfer observables and (p,p&#39;gamma) coincident spin observables, we have made a model-independent determination of the complete scattering amplitude for the 15.11 MeV, 1+, T=1 state in 12C at an incident proton energy of 200 MeV, for four center of mass proton scattering angles ran

Wlodzimierz M. Tulczyjew, Pawel Urbanski

A comparative analysis of two different versions of the Legendre transformation is presented. We provide an almost complete although somewhat superficial review of the geometric background for analytical mechanics. Complete coordinate characterizations of all structures are provided. Intrinsic constructions of most of the objects are given. Examples of appli

J. Donin

Let M be a manifold with an action of a Lie group G, $\A$ the function algebra on M. The first problem we consider is to construct a $U_h(\g)$ invariant quantization, $\A_h$, of $\A$, where $U_h(\g)$ is a quantum group corresponding to G. Let s be a G invariant Poisson bracket on M. The second problem we consider is to construct a $U_h(\g)$ invariant two par

Robert L. Bryant

The purpose of this article is to classify the real hypersurfaces in complex space forms of dimension 2 that are both Levi-flat and minimal. The main results are as follows: When the curvature of the complex space form is nonzero, there is a 1-parameter family of such hypersurfaces. Specifically, for each one-parameter subgroup of the isometry group of the c

Gregory J. Galloway

A maximum principle for C^0 null hypersurfaces is obtained and used to derive a splitting theorem for spacetimes which contain null lines. As a consequence of this null splitting theorem, it is proved that an asymptotically simple vacuum (Ricci flat) spacetime which contains a null line is isometric to Minkowski space.

Attila Andai, Peter W. Michor, Denes Petz

The curvature tensor and the scalar curvature are computed in the space of positive definite real matrices endowed by the Kubo-Mori inner product as a Riemannian metric.

Misha Verbitsky

For any subvariety of a compact holomorphic symplectic Kaehler manifold, we define the number W(X), which we call Wirtinger number. We show that $W(X)\leq 1$, and the equality is reached if and only if the subvariety $X\subset M$ is trianalytic, i. e. compactible with the hyperkaehler structure on M. For a sequence $X_1 \arrow X_2 \arrow ... X_n\arrow M$ of

Stefan Kebekus, Thomas Peternell, Andrew J. Sommese, Jaroslaw Wisniewski

We prove that a projective contact manifold X with second Betti number at least 2 whose canonical bundle K_X is not nef, is always the projectivised tangent bundle P(T_Y) of a projective manifold Y. It is expected that the canonical bundle of a projective contact manifold is never nef; we prove this unless possibly K_X^2 = 0 and K_X is not numerically trivia

Pietro Fre&#39;, Leonardo Gualtieri, Piet Termonia

In this paper, relying on previous results of one of us on harmonic analysis, we derive the complete spectrum of Osp(3|4) X SU(3) multiplets that one obtains compactifying D=11 supergravity on the unique homogeneous space N^{0,1,0} that has a tri-sasakian structure, namely leads to N=3 supersymmetry both in the four-dimensional bulk and on the three-dimensio

Shijong Ryang

We construct the retarded Green function and the Hadamard function in the Lorentzian (d+1)-dimensional anti-de Sitter spacetime for the Poincaré coordinate by performing the mode integration directly. We explore the structure of singularities for the position-space Feynman propagator derived from them. The boundary scaling limits of the bulk Feynman propagat

D. J. Broadhurst

A dimensionally continued background-field method makes the rationality of the 4-loop quenched QED beta function far more reasonable than had previously appeared. After 33 years of quest, dating from Rosner&#39;s discovery of 3-loop rationality, one finally sees cancellation of zeta values by the trace structure of individual diagrams. At 4-loops, diagram-by

U. Baur, R. Brown

We celebrate two birthdays connected with the radiation zero phenomenon. First, a striking dip in the theoretical angular distributions of radiative weak-boson production was discovered twenty years ago. The key experimental interest is that this will not occur in any deviation from the standard model. Second, the classical training of Stanley Brodsky began

Jae-weon Lee, Kyungsub Kim, Chul H. Lee, Ji-ho Jang

The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibr

Y. Schroder

In quantum chromodynamics (QCD), the binding energy of an infinitely heavy quark--antiquark pair in a color singlet state can be calculated as a function of the distance. We investigate this static potential of QCD perturbatively and calculate the full two-loop coefficient, correcting an earlier result. Beyond this order, the perturbative expansion breaks do

Paul Hoyer, Stephane Peigne

We evaluate the Psi&#39; to J/Psi ratio in diffractive photoproduction in a light-cone framework, using charmonium wave functions extracted from non-relativistic potential models. Contrary to current belief, we find that the best estimate for the ratio is a factor 2 to 5 below the data. The measured ratio constrains the distribution of the charm quark-antiqu

Bernd A. Kniehl, Lennart Zwirner

The fragmentation functions D_{a -> H}(x,mu^2) of a heavy hadron H, with mass m_H, satisfy the phase-space constraint D_{a - > H}(x,mu^2)=0 for x < m_H^2/mu^2, which is violated by the naive mu^2 evolution equations. Using appropriately generalized mu^2 evolution equations, we reconsider the inclusive hadroproduction of prompt J/psi mesons with high transver

C. Korthals-Altes, A. Kovner, M. Stephanov

We show that the deconfinement phase transition in the pure Yang-Mills theory can be characterized by the change of behaviour the spatial &#39;t Hooft loop, V(C). In the confining phase V has a perimeter law behaviour V(C)= exp{-mP(C)}, while in the deconfined phase it has the area law behaviour V(C)= exp{-αS(C)}. We show that the area law behaviour of the &

Yi-Bing Ding, Xue-Qian Li, Pong-Nian Shen

We would comment on the results of the paper &#34;a unified scheme for flavored mesons and baryons&#34; (P.C.Vinodkumar, J.N.Panandya, V.M.Bannur, and S.B.Khadkikar Eur. Phys. J. A4(1999)83), and point out some inconsistencies and mistakes in the work for solving the Dirac equation. In terms of an example for a single particle we investigate the reliability

A. Misra

We construct a complete list of O(q^4) terms directly within Heavy Baryon Chiral Perturbation Theory (HBChPT) in the absence of external fields and assuming isospin symmetry. In addition to a phase rule recently developed (NPA646, 343, &#39;99), a variety of algebraic identities and reparameterization invariance, are used to ensure linear independence of the

Jihn E. Kim, Bumseok Kyae, Jae Sik Lee

The forms of quark and lepton mass matrices are severely restricted in the $R_F$ parity model. We determine the form of the quark mass matrix first and derive the form of the neutrino mass matrix. For this to be consistent with the present experiments, we conclude that the masses of the superpartners of the right--handed down-type squarks and sneutrino vacuu

A. Misra

Paper withdrawn in favor of hep-ph/9909498

C. Alexandrou, H. Panagopoulos, E. Vicari

We compute the ratio $Λ_L/Λ_{\bar{MS}}$ between the scale parameter $Λ_L$, associated with a lattice formulation of QCD using the overlap-Dirac operator, and $Λ_{\bar{MS}}$ of the $\bar{\rm MS}$ renormalization scheme. To this end, the necessary one-loop relation between the lattice coupling $g_0$ and the coupling renormalized in the $\bar{\rm MS}$ scheme is

D. Muller

We present selected results on strong interaction physics from the SLD experiment at the SLAC Linear Collider. We report on several new studies of 3- and 4-jet hadronic Z decays, in which jets are identified as quark, antiquark or gluon. The 3-jet Z^0->b\bar{b}g rate is sensitive to the b-quark mass; prospects for measuring m_b are discussed. The gluon energ

Toshinori Abe, representing the SLD Collaboration

During 1996, the SLD collaboration completed construction and began operation of a new charge-coupled device (CCD) vertex detector (VXD3). Since then, its performance has been studied in detail and a new topological vertexing technique has been developed. In this paper, we discuss the design of VXD3, procedures for aligning it, and the tracking and vertexing

P. Astone, G. D&#39;Agostini

We consider the issue of reporting the result of search experiment in the most unbiased and efficient way, i.e. in a way which allows an easy interpretation and combination of results and which do not depend on whether the experimenters believe or not to having found the searched-for effect. Since this work uses the language of Bayesian theory, to which most

Sandro Palestini

Direct CP violation is studied in two pion decays of the neutral kaon. Using data collected in the first beam period in 1997, the result for the parameter Re(epsilon&#39;/epsilon) is (18.5+/-4.5(stat)+/-5.8(syst))x10^(-4).

Lee Lindblom, Gregory Mendell

The analogs of r-modes in superfluid neutron stars are studied here. These modes, which are governed primarily by the Coriolis force, are identical to their ordinary-fluid counterparts at the lowest order in the small angular-velocity expansion used here. The equations that determine the next order terms are derived and solved numerically for fairly realisti

Bruce Allen, Wensheng Hua, Adrian Ottewill

A technique is described for removing interference from a signal of interest (&#34;channel 1&#34;) which is one of a set of N time-domain instrumental signals (&#34;channels 1 to N&#34;). We assume that channel 1 is a linear combination of &#34;true&#34; signal plus noise, and that the &#34;true&#34; signal is not correlated with the noise. We also assume th

Herbert Balasin

We investigate the structure of the gravitational field generated by a massless particle moving on the horizon of an arbitrary (stationary) black hole. This is done by employing the generalized Kerr-Schild class where we take the null generators of the horizon as the geodetic null vector-field and a scalar function which is concentrated on the horizon.

Olivier Devillers, Asish Mukhopadhyay

Given a finite set of non-collinear points in the plane, there exists a line that passes through exactly two points. Such a line is called an ordinary line. An efficient algorithm for computing such a line was proposed by Mukhopadhyay et al. In this note we extend this result in two directions. We first show how to use this algorithm to compute an ordinary c

Ar. Abanov, Andrey V. Chubukov

We use the Scalapino-White relation between the condensation energy and the difference between the dynamical structure factor in the normal and the superconducting states to compute the condensation energy in the spin-fermion model. We show that at strong coupling, the extra low-frequency spectral weight associated with the resonance peak in the dynamical st

M. Payami

In the framework of spherical geometry for jellium and local spin density approximation, we have obtained the equilibrium $r_s$ values, $\bar{r}_s(N,ζ)$, of neutral and singly ionized &#34;generic&#34; $N$-electron clusters for their various spin polarizations, $ζ$. Our results reveal that $\bar{r}_s(N,ζ)$ as a function of $ζ$ behaves differently depending o

Jorge Kohanoff, Sandro Scandolo, Stefano de Gironcoli, Erio Tosatti

A new class of strongly infrared active structures is identified for phase III of compressed molecular H2 by constant-pressure ab initio molecular dynamics and density-functional perturbation calculations. These are planar quadrupolar structures obtained as a distortion of low-pressure quadrupolar phases, after they become unstable at about 150 GPa due to a

M. Cristina Marchetti, David R. Nelson

Patterned irradiation of cuprate superconductors with columnar defects allows a new generation of experiments which can probe the properties of vortex liquids by forcing them to flow in confined geometries. Such experiments can be used to distinguish experimentally between continuous disorder-driven glass transitions of vortex matter, such as the vortex glas

P. Chandra, L. B. Ioffe

We study the distribution of attraction basins as a function of energy in simple glasses. We find that it is always broad. Furthermore we identify two types of glasses, both with an exponentially large number of metastable states. In one type the largest attraction basin is exponentially small, whereas in the other it is polynomially small in the system size

Luis F. Lago-Fernandez, Ramon Huerta, Fernando Corbacho, Juan A. Siguenza

We have investigated the role that different connectivity regimes play on the dynamics of a network of Hodgkin-Huxley neurons by computer simulations. The different connectivity topologies exhibit the following features: random connectivity topologies give rise to fast system response yet are unable to produce coherent oscillations in the average activity of

V. Rzhevskii, G. Roepke

Strong nonlinear elastic effects arise due to the Lifshitz transition associated with a change in the Fermi surface topology. It is shown that an electronic contribution to the elastic characteristics of cuprates becomes important if the chemical potential is near but not too near the Van Hove critical energy $ε_c$. In the case of a saddle point singularity

Haye Hinrichsen, Andrea Jimenez-Dalmaroni, Yadin Rozov, Eytan Domany

A simple model for flowing sand on an inclined plane is introduced. The model is related to recent experiments by Douady and Daerr [Nature 399, 241 (1999)] and reproduces some of the experimentally observed features. Avalanches of intermediate size appear to be compact, placing the critical behavior of the model into the universality class of compact directe

G. Bouzerar, O. Legeza, T. Ziman

We show that to describe properly the low energy excitations of $CuGeO_{3}$ one must include the effects of a transverse antiferromagnetic coupling, which is estimated to be $J_{\perp}=0.15 J$. Owing to this coupling the frustration in the chains is significantly lower than recent 1D estimates based on purely one-dimensional arguments, we find $J_{2}=0.2 J$.

I. V. Kuzmenko, V. M. Rozenbaum

We consider high-frequency local vibrations anharmonically coupled with low-frequency modes in a planar lattice of adsorbed molecules. The effect of lateral intermolecular interactions on the spectral line shape for local vibrations is analyzed in the limit of the high density of adsorbed molecules. It is shown that the spectral line positions and widths dep

Junzo Chihara

Formulas to describe the photoabsorption and the photon scattering by a plasma or a liquid metal are derived in a unified manner with each other. It is shown how the nuclear motion, the free-electron motion and the core-electron behaviour in each ion in the system determine the structure of photoabsorption and scattering in an electron-ion mixture. The absor

Y. -H. Nie, Y. -B. Zhang, J. -Q. Liang, H. J. W. Mueller-Kirsten

Starting from the Hamiltonian operator of the noncompensated two-sublattice model of a small antiferromagnetic particle, we derive the effective Lagrangian of a biaxial antiferromagnetic particle in an external magnetic field with the help of spin-coherent-state path integrals. Two unequal level-shifts induced by tunneling through two types of barriers are o

Thomas Schreiber, Andreas Schmitz

Before we apply nonlinear techniques, for example those inspired by chaos theory, to dynamical phenomena occurring in nature, it is necessary to first ask if the use of such advanced techniques is justified &#34;by the data&#34;. While many processes in nature seem very unlikely a priori to be linear, the possible nonlinear nature might not be evident in spe

Brian R. La Cour, William C. Schieve

We consider a general system of n noninteracting identical particles which evolve under a given dynamical law and whose initial microstates are a priori independent. The time evolution of the n-particle average of a bounded function on the particle microstates is then examined in the large n limit. Using the theory of large deviations, we show that if the in

G. Gonzalez, C. Laws

The results of a new spectroscopic analysis of HD75289, recently reported to harbor a Jovian-mass planet, are presented. From high-resolution, high-S/N ratio spectra, we derive [Fe/H] = +0.28 +/- 0.05 for this star, in agreement with the spectroscopic study of Gratton et al., published 10 years ago. In addition, we present a re-analysis of the spectra of Ups