December 1998 arXiv papers — page 9

T. Schneider, J. M. Singer

The $c$-axis resistivity measurements in YBa_2Cu_4O_8 from Hussey et al. for magnetic field orientations along the c-axis as well as within the ab-plane are analyzed and interpreted using the scaling theory for static and dynamic classical critical phenomena. We identify a superconductor to normal conductor transition for both field orientations as well as a

Dirk Helbing, Martin Treiber

Have you been suffering from traffic jams lately and asking yourself why freeways are no free ways anymore? After several great advances in traffic theory, Korean physicists have now offered an interpretation of a recently discovered state of congested traffic, called ``synchronized'' traffic. Their fluid-dynamic simulations can be a useful tool for

V. I. Yukalov, E. P. Yukalova

Spin dynamics of a polarized spin system is studied when the latter is coupled with a resonant electric circuit and is under the action of an external pumping supporting a stationary nonequilibrium magnetization. A complete classification of possible regimes of spin motion is given. In addition to seven regimes considered earlier, two other transient regimes

O. Golinelli, Th. Jolicoeur, E. Sorensen

We study the magnetic excitation spectrum of the S=1 quantum Heisenberg spin chain with Hamiltonian : H = sum_i cos(theta) S_i S_i+1 + sin(theta) (S_i S_i+1)^2. We focus on the range -pi/4 < theta < +pi/4 where the spin chain is in the gapped Haldane phase. The excitation spectrum and static structure factor is studied using direct Lanczos diagonalization of

V. N. Shilov, N. I. Zharkikh

The electroosmotic transfer (ratio of velocity of liquid to electric current density) and conductivity of disperse system were calculated as functions of volume fraction of disperse particles. The considered model of electric double layer (EDL) was generalized by taking into account the reducing dissolving ability of liquid near the surface (non-dissolving b

Lingjun Wang, Guanghong Wei, Jian Zi

A planar force-constant model is developed for longitudinal phonons of wurtzite GaN and AlN propagating along the [0001] direction. The proposed model is then applied to the study of the phonon modes in hexagonal GaN/AlN superlattices in the longitudinal polarization. The confinement of the superlattice phonon mode is discussed.

H. C. Lee

The point contact tunneling conductance between edges of the spin singlet $ν=2/3,\hat{K}=(3/3/0)$ quantum Hall states is studied both in the quasiparticle tunneling picture and in the electron tunneling picture. Due to the interplay of Zeeman splitting and the long range Coulomb interaction between edges of opposite chirality novel spin excitations emerge, a

Nikolay V. Dokholyan, Sergey V. Buldyrev, H. Eugene Stanley, Eugene I. Shakhnovich

Background: Many attempts have been made to resolve in time the folding of model proteins in computer simulations. Different computational approaches have emerged. Some of these approaches suffer from the insensitivity to the geometrical properties of the proteins (lattice models), while others are computationally heavy (traditional MD). Results: We use a re

V. I. Yukalov

The basic mathematical properties of Green&#39;s functions used in statistical mechanics as well as the equations defining these functions and the techniques of solving these equations are reviewed. An approach is presented called the Correlated Iteration Theory, which has been developed by the author. This approach differs from all other known variants of p

Niels Asger Mortensen, Karsten Flensberg, Antti-Pekka Jauho

We study the angle dependence of the Andreev scattering at a semiconductor-superconductor interface, generalizing the one-dimensional theory of Blonder, Tinkham and Klapwijk. An increase of the momentum parallel to the interface leads to suppression of the probability of Andreev reflection and increase of the probability of normal reflection. We show that in

Antonio Politi, Annette Witt

A class of simplified measures is constructed to capture the key features of generic spatio-temporally chaotic systems. A combined analytical and numerical investigation allows us to extablish the scaling beahviour of the fractal dimension in open systems. Our results improve a previous conjecture and, what is more important, furnish a clear framework for bo

Dipak Munshi, Peter Coles, Adrian L. Melott

The highly nonlinear regime of gravitational clustering is characterized by the presence of scale-invariant form of many-body correlation functions. Useful insights can be obtained by investigating the consequences of a generic scaling {\em ansatz}. Extending earlier studies by Bernardeau & Schaeffer (1992) we calculate the detailed consequences of such scal

A. S. Szalay, R. J. Brunner

Astronomy is entering a new era as multiple, large area, digital sky surveys are in production. The resulting datasets are truly remarkable in their own right; however, a revolutionary step arises in the aggregation of complimentary multi-wavelength surveys (i.e. the cross-identification of a billion sources). Federating these different datasets, however, is

R. Ansari, M. Auriere, P. Baillon, A. Bouquet

AgapeZ1 is the brightest and the shortest duration microlensing candidate event found in the Agape data. It occured only 42&#34; from the center of M31. Our photometry shows that the half intensity duration of the event6 is 4.8 days and at maximum brightness we measure a stellar magnitude of R=18.0 with B-R=0.80 mag color. A search on HST archives produced a

V. I. Dokuchaev, Yu. N. Eroshenko, L. M. Ozernoy

Recently we have elaborated a new cosmological model of gamma-ray burst (GRB) origin (1998, ApJ 502, 192), which employs the dynamical evolution of central dense stellar clusters in the galactic nuclei. Those clusters inevitably contain a large fraction of compact stellar remnants (CSRs), such as neutron stars (NSs) and stellar mass black holes (BHs), and cl

Keith Horne

Echo mapping exploits light travel time delays, revealed by multi-wavelength variability studies, to map the geometry, kinematics, and physical conditions of reprocessing sites in photo-ionized gas flows. In AGNs, the ultra-violet to near infra-red light arises in part from reprocessing of EUV and X-ray light from a compact and erratically variable source in

Albert A. Zijlstra, Dante Minniti

We have obtained V and I-band photometry for about 700 stars in the field of the dwarf irregular galaxy IC 5152, previously considered a possible member of the Local Group. Deep VI color-magnitude diagrams are presented of the main body of this galaxy and of a nearby field. We infer a distance by comparison with the VI color-magnitude diagrams of similar gal

W. G. Roberge, A. Lazarian

We present extensive calculations on the efficiency of grain alignment by the Davis-Greenstein mechanism. We model the grains as oblate spheroids with arbitrary axis ratios. Our description of the grain dynamics includes (i) magnetic dissipation and the inverse process driven by thermal fluctuations in the grain magnetization; (ii) gas-grain collisions and t

Stacy McGaugh

I explore some consequences of Milgrom&#39;s modified dynamics for cosmology. There appear to be two promising tests for distinguishing MOND from CDM: (1) the rate of growth of structure and (2) the baryon fraction. These should be testable with observations of clusters at high redshift and the microwave background, respectively.

Stacy McGaugh

I review current theories of disk galaxy formation. All fail in the light of recent data for low surface brightness galaxies. The difficulty stems from the presence of a unique acceleration scale in the data.

Guido De Marchi

Deep HST-WFPC2 observations of the stellar population in the globular cluster Omega Cen (NGC 5139) have been used to measure the luminosity function of main sequence stars at the low-mass end. Two fields have been investigated, located respectively ~4.6&#39; and ~7&#39; away from the cluster center, or near the half-light radius of this cluster (~4.8&#39;).

S. Pellegrini

We present the results of the analysis of the BeppoSAX LECS and MECS pointed observation of the E4 galaxy NGC 3923, for which previous X-ray measurements had given a medium X-ray to optical ratio Lx/Lb. The spectral analysis over (0.5-10) keV reveals that the best representation of the data is the superposition of two thermal components at temperatures of 0.

Daniel Kunth

I discuss the properties of gas-rich forming galaxies. I particularly emphasize the latest results on Lyman alpha emission that are relevant to the search of distant young galaxies. The interdependance of the Lyman alpha escape with the properties of the ISM in starburst galaxies is outlined. A new model from G. Tenorio-Tagle and his collaborators explaining

Joseph Silk, Rychard J. Bouwens

The forwards approach to galaxy formation and evolution is extremely powerful but leaves several questions unanswered. Foremost among these is the origin of disks. A backwards approach is able to provide a more realistic treatment of star formation and feedback and provides a practical guide to eventually complement galaxy formation ab initio.

Chris Flynn, Andrew Gould, John Bahcall

We describe a program of star counts in the range 19 < I < 26 made with the WFPC cameras aboard the Hubble Space Telescope. Red (V-I > 1.0) stars at these magnitudes are primarily disk and spheroid M dwarfs. The stars are found both on dedicated images as part of the parallel program and by using appropriate archive data. We measure the faint end of the lumi

Yu Gao, Philip M. Solomon

Most luminous infrared galaxies (LIGs) are closely interacting/merging systems rich in molecular gas. We study here the relationship between the stage of the galaxy-galaxy interactions, the molecular gas mass, and the star formation rate as deduced from the infrared luminosity L_IR in LIGs. We find a correlation between the CO(1-0) luminosity (a measure of m

Andrey Kravtsov, Anatoly Klypin

We present results from a study of bias and its evolution for galaxy-size halos in a large, high-resolution simulation of a LCDM model. We consider the evolution of bias estimated using two-point correlation function (b_xi), power spectrum (b_P), and a direct correlation of smoothed halo and matter overdensity fields (b_d). We present accurate estimates of t

Xiangdong Shi, George M. Fuller

In the paper &#34;Big Bang Nucleosynthesis and Active-Sterile Neutrino Mixing: Evidence for Maximal Muon-Neutrino/Sterile-Neutrino Mixing in Super Kamiokande&#34; (astro-ph/9810075), we suggested that to evade the Big Bang Nucleosynthesis exclusion of the muon neutrino to sterile neutrino oscillation explanation of the Super Kamiokande data, the tau neutrino

L. Pulone, G. De Marchi, F. Paresce

Deep images of the galactic globular cluster M4 taken at various locations with the NIC3 and the WFPC2 cameras on HST were used to derive detailed local optical and near IR luminosity functions. White dwarfs have been detected for the first time on a color sequence at constant luminosity in the F110W band. Transformation of the observed luminosity functions

Alexander I. Olemskoi, Valerii A. Brazhnyi

On the basis of Langevin equation the optimal SUSY field scheme is formulated to discribe a non-equilibrium thermodynamic system with quenched disorder and non-ergodicity effects. Thermodynamic and isothermal susceptibilities, memory parameter and irreversible response are determined at different temperatures and quenched disorder intensities.

Nikolay V. Dokholyan, Sergey V. Buldyrev, H. Eugene Stanley, Eugene I. Shakhnovich

Molecular dynamics simulations of folding in an off-lattice protein model reveal a nucleation scenario, in which a few well-defined contacts are formed with high probability in the transition state ensemble of conformations. Their appearance determines folding cooperativity and drives the model protein into its folded conformation.

S. Alama, A. J. Berlinsky, L. Bronsard, T. Giorgi

We consider the problem of superconducting Ginzburg-Landau (G-L) vortices with antiferromagnetic cores which arise in Zhang&#39;s SO(5) model of antiferromagnetism (AF) and high temperature superconductivity (SC). This problem was previously considered by Arovas et al. who constructed approximate &#34;variational&#34; solutions, in the large kappa limit, to

Yves A. Gallant, Abraham Achterberg

We consider the acceleration of charged particles at the ultra-relativistic shocks, with Lorentz factors Γ_s >> 1 relative to the upstream medium, arising in relativistic fireball models of gamma-ray bursts (GRBs). We show that for Fermi-type shock acceleration, particles initially isotropic in the upstream medium can gain a factor of order Γ_s^2 in energy i

J. B. Marston, Shan-Wen Tsai

We show that the localization transition in the integer quantum Hall effect as described by the Chalker-Coddington network model is quantum critical. We first map the anisotropic network model to the problem of diagonalizing a one-dimensional non-Hermitian non-compact supersymmetric lattice Hamiltonian of interacting bosons and fermions. Its behavior is inve

L. E. Ibáñez, C. Muñoz, S. Rigolin

We study different phenomenological aspects of compact, D=4, N=1 Type IIB orientifolds considered as models for unification of the standard model and gravity. We discuss the structure of the compactification, string and unification scales depending on the different possible D-brane configurations. It is emphasized that in the context of Type I models the $M_

Leonid Burakovsky, Philip R. Page, Terry Goldman

We generalize Schwinger&#39;s original mass formula to the case of an additional isosinglet mixing with the nonet mesons. We then make further generalization to either (i) an arbitrary number of additional isosinglets mixing with nonet mesons, or (ii) an arbitrary number of mesons mixing with an additional isosinglet. In the former case, we present an explic

Balázs Molnár, Mihály G. Benedict

By introducing the shape invariant Lie algebra spanned by the SUSY ladder operators plus the unity operator, a new basis is presented for the quantum treatment of the one-dimensional Morse potential. In this discrete, complete orthonormal set, which we call the pseudo number states, the Morse Hamiltonian is tridiagonal. By using this basis we construct coher

Marc Henneaux, Bernard Knaepen

The general solution of the antifield-independent Wess-Zumino consistency condition is worked out for models involving exterior form gauge fields of arbitrary degree. We consider both the free theory and theories with Chapline-Manton couplings. Our approach relies on solving the full set of descent equations by starting from the last element down (&#34;botto

Frank Garvan

This is a tutorial for using a new q-series Maple package. The package includes facilities for conversion between q-series and q-products and finding algebraic relations between q-series. Andrews found an algorithm for converting a q-series into a product. We provide an implementation. As an application we are able to effectively find finite q-product factor

Jordi Miralda-Escude, Martin Haehnelt, Martin J. Rees

A model of the density distribution in the intergalactic medium, motivated by that found in numerical simulations, is used to demonstrate the effect of a clumpy IGM and discrete sources on the reionization of the universe. In an inhomogeneous universe reionization occurs outside-in, starting in voids and gradually penetrating into overdense regions. Reioniza

L. F. Santos, C. O. Escobar

We find an analogy between turbulence and the dynamics of the continuous spontaneous localization model (CSL) of the wave function. The use of a standard white noise in the localization process gives Richardson&#39;s t^3 law for the turbulent diffusion, while the introduction of an affine noise in the CSL allows us to obtain the intermittency corrections to

Jorma Louko, Kristin Schleich

We consider scalar field theory on the RP^3 de Sitter spacetime (RP3dS), which is locally isometric to de Sitter space (dS) but has spatial topology RP^3. We compare the Euclidean vacua on RP3dS and dS in terms of three quantities that are relevant for an inertial observer: (i) the stress-energy tensor; (ii) the response of an inertial monopole particle dete

N. Reggiani, M. M. Guzzo, J. H. Colonia, P. C. de Holanda

Taking into account the stringent limits from helioseismology observations on possible matter density fluctuations described by magnetohydrodynamics theory, we find the corresponding time variations of solar neutrino survival probability due to the resonant spin-flavor precession phenomenon with amplitude of order O(10%). We discuss the physics potential of

Riccardo Barbieri, Lawrence J. Hall, Andrea Romanino

The relations $|V_{ub}/V_{cb}|=(m_u/m_c)^{1/2}$ and $|V_{td}/V_{ts}|=(m_d/m_s)^{1/2}$ between the CKM matrix elements and the quark masses are shown to imply a remarkably precise determination of the CKM unitarity triangle or of the Wolfenstein parameters $ρ$, $η$ consistent with the data so far. We view this as a clean test of a quark mass texture neatly ar

Chun Liu, Jeonghyeon Song

The four light neutrino scenario, which explains the atmosphere, solar and LSND neutrino experiments, is studied in the framework of the seesaw mechanism. By taking both the Dirac and Majorana mass matrix of neutrinos to be singular, the four neutrino mass spectrum consisting of two almost degenerate pairs separated by a mass gap $\sim 1$ eV is naturally gen

Hungsoo Kim, Soo-Young Lee, Sahng-Kyoon Yoo, D. K. Park

Phase transition of decay rate from quantum tunneling to thermal activity regimes is investigated in (3+1)-dimensional field theories with symmetry breaking term $fϕ$. By applying the two independent criteria for the sharp first-order transition to the same model, the upper and lower bounds of critical value of the symmetry breaking parameter are obtained. U

Dae-Yup Song

For a harmonic oscillator with time-dependent (positive) mass and frequency, an unitary operator is shown to transform the quantum states of the system to those of a harmonic oscillator system of unit mass and time-dependent frequency, as well as operators. For a driven harmonic oscillator, it is also shown that, there are unitary transformations which give

G. J. Gounaris, P. I. Porfyriadis, F. M. Renard

We point out a few remarkable properties of the $γγ\toγγ$ process at high energy. They should allow to search for effects of new particles and interactions. We give illustrations with threshold effects due to pairs of new charged particles (charginos, charged Higgses, sfermions), resonance effects due to s-channel production of neutral scalars (standard or s

Ivo Eschrich

In parallel to charm hadroproduction the experiment SELEX (E781) at Fermilab is pursuing a rich hyperon physics program. SELEX employs a 600 GeV/c beam consisting of 50% \Sigma^- and \pi^- each. The three-stage magnetic spectrometer covering 0.1 <= x_F <= 1.0 features a high-precision silicon vertex system, broad-coverage particle identification using TRD an

Yoichi Ando, J. Takeya, Yasushi Abe, K. Nakamura

The thermal conductivity κof Bi-2212 is measured in pure and Zn-doped crystals as a function of temperature and magnetic field. The in-plane resistivity is also measured on the identical samples. Using these data, we make a crude estimate of the impurity-scattering rate Γof the pure and the Zn-doped crystals. Our measurement show that the &#34;plateau&#34; i

E. Eisenberg, R. Berkovits

We study the influence of on-site disorder on the magnetic properties of the ground state of the infinite $U$ Hubbard model. We find that for one dimensional systems disorder has no influence, while for two dimensional systems disorder enhances the spin polarization of the system. The tendency of disorder to enhance magnetism in the ground state may be relev

Nicole F. Bell, Raymond R. Volkas

A consequence of the evaporation of primordial black holes in the early universe may be the generation of mirror matter. This would have implications with regard to dark matter, and the number of light particle species in equilibrium at the time of big bang nucleosynthesis. The possibilities for the production of mirror matter by this mechanism are explored.

M. Nishiuchi, K. Koyama, Y. Maeda, K. Asai

We report the ASCA results of the bursting X-ray pulsar \gro, which was observed in February 1996 and March 1997. The source flux in the 2--10 keV band was $2.0\times10^{-8}$ erg/sec/cm$^2$ in 1996 and $5.0\times10^{-9}$ erg/sec/cm$^2$ in 1997. We detected 12 and 17 Type II bursts during the two observations with mean bursting intervals of about 27 min and 3

David W. Neilsen, Matthew W. Choptuik

We investigate the gravitational collapse of a spherically symmetric, perfect fluid with equation of state P = (Gamma -1)rho. We restrict attention to the ultrarelativistic (``kinetic-energy-dominated&#39;&#39;, ``scale-free&#39;&#39;) limit where black hole formation is anticipated to turn on at infinitesimal black hole mass (Type II behavior). Critical sol

D. Gomez-Ullate, S. Lafortune, P. Winternitz

The Lie point symmetries of a coupled system of two nonlinear differential-difference equations are investigated. It is shown that in special cases the symmetry group can be infinite dimensional, in other cases up to 10 dimensional. The equations can describe the interaction of two long molecular chains, each involving one type of atoms.

Ming-Hsien Tu, Jiin-Chang Shaw

A study of Hamiltonian structures associated with supersymmetric Lax operators is presented. Following a constructive approach, the Hamiltonian structures of Inami-Kanno super KdV hierarchy and constrained modified super KP hierarchy are investigated from the reduced supersymmetric Gelfand-Dickey brackets. By applying a gauge transformation on the Hamiltonia

I. G. Korepanov, S. Saito

We put forward one of the forms of functional pentagon equation (FPE), known from the theory of integrable models, as an algebraic explanation to the phenomenon known in physics as s<->t duality. We present two simple geometrical examples of FPE solutions, one of them yielding in a particular case the well-known Veneziano expression for 4-particle amplitude.

Kurt Gottfried

The classical limit of the Schrodinger equation implies the orthodox statistical interpretation for degrees of freedom in finite-dimensional subspaces of the full Hilbert space, but the argument presented does not imply the Born interpretation for degrees of freedom that have a classical counterpart.

Carl M. Bender, Gerald V. Dunne

A precise calculation of the ground-state energy of the complex PT-symmetric Hamiltonian $H=p^2+{1/4}x^2+i λx^3$, is performed using high-order Rayleigh-Schrödinger perturbation theory. The energy spectrum of this Hamiltonian has recently been shown to be real using numerical methods. The Rayleigh-Schrödinger perturbation series is Borel summable, and Padé s

M. Holzmann, Y. Castin

We calculate the pair correlation function of an interacting Bose gas in a harmonic trap directly via Path Integral Quantum Monte Carlo simulation for various temperatures and compare the numerical result with simple approximative treatments. Around the critical temperature of Bose-Einstein condensation, a description based on the Hartree-Fock approximation

A. Derevianko, W. R. Johnson, M. S. Safronova, J. F. Babb

The van der Waals coefficients for the alkali-metal atoms from Na to Fr interacting in their ground states, are calculated using relativistic ab initio methods. The accuracy of the calculations is estimated by also evaluating atomic static electric dipole polarizabilities and coefficients for the interaction of the atoms with a perfectly conducting wall. The

Hilton W. Chan, Joshua C. Long, John C. Price

We present a procedure for the design and construction of a passive, multipole, mechanical high-stop vibration isolator. The isolator, consisting of a stack of metal disks connected by thin wires, attenuates frequencies in the kilohertz range, and is suited to both vacuum and cryogenic environments. We derive an approximate analytical model and compare its p

N. Itaco, A. Covello, A. Gargano

In this paper, we present some results of a particle-rotor model study of 176Lu. In particular, we consider the two lowest K=1+ balds, which present a rather large odd-even staggering. This effect, which may be traced to direct Coriolis coupling with Newby-shifted K=0+ bands, is of great interest since it gives information on the proton-neutron interaction.

P. Banerjee

We investigate the post-acceleration of the $^{10}$Be fragment in Coulomb breakup reaction of the halo nucleus $^{11}$Be, assuming that the excitation of the projectile is to states in the low energy continuum. The method used retains all finite-range effects associated with the interactions between the breakup fragments and can use realistic wave functions

M. J. Bennett, J. L. Nagle

We calculate the survival probability of $J/Ψ$ particles in various colliding systems using a Glauber model. An analysis of recent data has reported a $J/Ψ$-nucleon breakup cross section of 6.2$\pm$0.7 mb derived from an exponential fit to the ratio of $J/Ψ$ to Drell-Yan yields as a function of a simple, linearly-averaged mean path length through the nuclear

N. V. Mokhov, S. I. Striganov, A. Van Ginneken, S. G. Mashnik

Recent developments in the physical model of 1 MeV to 100 TeV hadron and lepton interactions with nuclei and atoms are described. These include a new nuclear cross section library, a model for soft pion production, the cascade-exciton model, the dual parton model, deuteron-nucleus and neutrino-nucleus interaction models, detailed description of muon, pion, a

Ezra Miller

Alexander duality has, in the past, made its way into commutative algebra through Stanley-Reisner rings of simplicial complexes. This has the disadvantage that one is limited to squarefree monomial ideals. The notion of Alexander duality is generalized here to arbitrary monomial ideals. It is shown how this duality is naturally expressed by Bass numbers, in

I. Dolgachev, J. Keum

We consider algebraic actions of a cyclic group of order p on a K3 surface defined over an algebraically closed field of characteristic p. We classify possible loci of fixed points as well as possible quotient surfaces.

Azamat M. Akhtyamov

An uniqueness theorem for the inverse problem in the case of a second-order equation defined on the interval [0,1] when the boundary forms contain combinations of the values of functions at the points 0 and 1 is proved. The auxiliary eigenvalue problems in our theorem are chose in the same manner as in Borg&#39;s uniqueness theorem are not as in that of Sado

Azamat M. Akhtyamov

The note contains the proof of the uniqueness theorem for the inverse problem in the case of $n$-th order differential equation.

Everett W. Howe

We define a Carmichael number of order m to be a composite integer n such that nth-power raising defines an endomorphism of every Z/nZ-algebra that can be generated as a Z/nZ-module by m elements. We give a simple criterion to determine whether a number is a Carmichael number of order m, and we give a heuristic argument (based on an argument of Erdos for the

David Berenstein, Robert G. Leigh

We study four-dimensional black hole configurations which result from wrapping M5-branes on a Calabi-Yau manifold, as well as U-dual realizations. Our aim is to understand the microscopic degrees of freedom responsible for the existence of bound states of multiple branes. The details depend on the chosen U-frame; in some cases, they are massless string junct

N. A. Obers, B. Pioline

Based on our work hep-th/9809039, we discuss how U-duality arises as an exact symmetry of M-theory from T-duality and 11D diffeomorphism invariance. A set of Weyl generators are shown to realize the Weyl group of SO(d,d,Z) and E_{d(d)}(Z), while Borel generators extend these finite groups into the full T- and U-duality groups. We discuss how the BPS states f

D. Seminara

We settle the ``apparent&#39;&#39; paradox present in thermal QED_3 that the perturbative series is not invariant, as manifested by the temperature dependence of the induced Chern-Simons term, by showing that large (unlike small) transformations and hence their Ward identities, are not perturbative order-preserving. Instead the thermal effective gauge field

George Chapline

It is shown that a simple model for 4-dimensional quantum gravity based on a 3-dimensional generalization of anyon superconductivity can be regarded as a discrete form of Polyakov&#39;s string theory. This suggests that there is a universal negative pressure that is on the order of the string tension divided by the square of the Robertson-Walker scale factor

M. L. Perl

This Fifth International WEIN Symposium is devoted to physics beyond the standard model. This talk is about tau lepton physics, but I begin with the question: do we know how to find new physics in the world of elementary particles? This question is interwoven with the various tau physics topics. These topics are: searching for unexpected tau decay modes; sea

J. H. Kuehn

Recent theoretical results in tau lepton physics and their implications for the experimental analysis are presented. The paper is split into the following chapters: 1. Introduction, 2. Weak Couplings, 3. Inclusive Decays, Perturbative QCD and Sum Rules, 4. Exclusive Decays, 5. Beyond the Standard Model.

Matthias Neubert

A general parametrization of the amplitudes for the rare two-body decays B -> pi K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the low-energy effective weak Hamiltonian. With the help of this parametrization, a model-independent analysis of the branching rat

Andrzej Czarnecki, Maciej Skrzypek

We present an analytic calculation of electron and tau O(alpha^3) loop effects on the muon anomalous magnetic moment. Computation of such three-loop diagrams with three mass scales is possible using asymptotic and eikonal expansions. An evaluation of a new type of eikonal integrals is presented in some detail.

M. V. Polyakov, A. Schaefer, O. V. Teryaev

The charm quark contribution to the first moment of $g_1(x,Q^2)$ is calculated using a heavy mass expansion of the divergence of the singlet axial current. It is shown to be small.

Andrzej J. Buras, Luca Silvestrini

We present a general scheme and scale independent parameterization of two-body non-leptonic B decay amplitudes which includes perturbative QCD corrections as well as final state interactions in a consistent way. This parameterization is based on the Next-to-Leading effective Hamiltonian for non-leptonic B decays and on Wick contractions in the matrix element

N. V. Mikheev, A. Ya. Parkhomenko, L. A. Vassilevskaya

The annihilation into axion $e^+ e^- \to a$ is investigated in a plasma and an external magnetic field. This process via a plasmon intermediate state has a resonant character at a particular energy of the emitted axion. The emissivity by $e^+ e^- \to a$ is compared with the axion cyclotron emissivity.

W. M. Alberico, M. B. Barbaro, S. M. Bilenky, J. A. Caballero

We consider ratios of elastic neutrino(antineutrino)-proton cross sections measured by the Brookhaven BNL-734 experiment and use them to obtain the neutral current (NC) over charged current (CC) neutrino-antineutrino asymmetry. We discuss the sensitivity of these ratios and of the asymmetry to the electric, magnetic and axial strange form factors of the nucl

W. Bernreuther, A. Brandenburg, M. Flesch

A striking manifestation of CP violation in the electroweak symmetry breaking sector would be the existence of neutral Higgs boson(s) with undefined CP parity. We analyse signatures of such a boson, with a mass of about 300 GeV or larger, produced in high energy proton-proton collisions at LHC energies in its top-quark antitop-quark decay channel. The large

Marcelo Hott, Georgios Metikas

We calculate the effective action for a constant magnetic field and a time-dependent time-component of the gauge field in 2+1 dimensions at finite temperature. We also discuss the behaviour of the charge density and the fermion condensate as order parameters of symmetry breaking.

J. Ellis, G. G. Ross, J. Williams

We suggest that the pseudo-rapidity cut dependence of diffractive deep-inelastic scattering events at HERA may provide a sensitive test of models of diffraction. A comparison with the experimental cross section shows that the Donnachie-Landshoff model and a simple two-gluon exchange model of the pomeron model are disfavoured. However a model with a direct co

Richard D. Ball, Hugh A. McL. Tallini

We review the current situation in polarized scattering experiments. We describe the theoretical interpretation of inclusive deep inelastic processes, the current experimental situation and perturbative analyses which extract structure functions and parton distribution functions. We also discuss various issues such as positivity constraints, small x and the

Ken Sasaki, Tsuneo Uematsu

The virtual photon structure function $g_1^γ(x,Q^2,P^2)$, which can be obtained in polarized $e^{+}e^{-}$ colliding-beam experiments, is investigated for $Λ^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the probe (target) photon. The analysis is made to next-to-leading order in QCD, in the framework of the QCD improved parton model with th

Yong Liu

We further investigate the probability that, weak CP phase originates in a certain geometry. We find that our postulation on weak CP Phase gives strict constraints on angle gamma in unitarity triangle DB and the element Vtd in Cabibbo-Kobayashi-Maskawa (CKM) matrix. The predicted Vtd is about 0.0086 and gamma about 75.3^o with the very narrow window respecti

The MACRO Collaboration, M. Ambrosio et al

We perform an indirect search for Weakly Interacting Massive Particles (WIMPs) using the MACRO detector to look for neutrino-induced upward-going muons resulting from the annihilation of WIMPs trapped in the Sun and Earth. The search is conducted in various angular cones centered on the Sun and Earth to accommodate a range of WIMP masses. No significant exce

A. O. Barvinsky

We propose the mechanism of quantum creation of the open Universe in the observable range of values of $Ω$. This mechanism is based on the no-boundary quantum state with the Hawking-Turok instanton applied to the model with a strong nonminimal coupling of the inflaton field. We develop the slow roll perturbation expansion for the instanton solution and obtai

Adrian P. Gentle, Daniel E. Holz, Warner A. Miller, John A. Wheeler

We construct initial data for a particular class of Brill wave metrics using Regge calculus, and compare the results to a corresponding continuum solution, finding excellent agreement. We then search for trapped surfaces in both sets of initial data, and provide an independent verification of the existence of an apparent horizon once a critical gravitational

B. Linet

By discussing the Cauchy problem, we determine the covariant equation of the characteristic hypersurfaces in a relativistic superfluid theory.

Takashi Nakamura, Ken-ichi Oohara

One of the most promising sources of gravitational radiation is coalescence of binary neutron stars or black holes. In order to study gravitational radiation at the merging phase of coalescing binary neutron stars which is called the last three-milliseconds, full general relativistic simulations are required. Since coalescence of binary stars is a completely

Peter M. Hines

We consider the structures given by repeatedly generalising the definition of finite state automata by symmetry considerations, and constructing analogues of transition monoids at each step. This approach first gives us non-deterministic automata, then (non-deterministic) two-way automata and bounded Turing machines --- that is, Turing machines where the rea

Stephan Busemann, Helmut Horacek

In order to support the efficient development of NL generation systems, two orthogonal methods are currently pursued with emphasis: (1) reusable, general, and linguistically motivated surface realization components, and (2) simple, task-oriented template-based techniques. In this paper we argue that, from an application-oriented perspective, the benefits of

Anand Bhattacharya, Igor Zutic, Oriol T. Valls, A. M. Goldman

In a recent Letter (Phys. Rev. Lett. 81, p.5640 (1998), cond-mat/9808249 v3), it was suggested that nonlocal effects may prevent observation of the nonlinear Meissner effect in YBCO. We argue that this claim is incorrect with regards to measurements of the nonlinear transverse magnetic moment, and that the most likely reason for a null result lies elsewhere.

A. Joshi, M. Ma, F. Mila, D. N. Shi

The Holstein-Primakoff transformation is generalized to develop a quantum flavor wave theory for spin systems with orbital degeneracy. Elementary excitations consist of spin, orbital, and spin-orbital waves. Spin and spin-orbital waves couple each other due to orbital anisotropy and Hund&#39;s rule, resulting in new modes observable by inelastic neutron scat

V. Gurarie, E. Rezayi

We continue the program started in cond-mat/9809384 and explain the statistics of the excitations for the generalizations of the paired states in the quantum Hall effect in terms of the parafermion statistics. We show that these excitations behave as combinations of bosons and parafermions. That generalizes the prior treatment of the paired (Pfaffian) state

T. E. Mason

Neutron scattering can provide detailed information about the energy and momentum dependence of the magnetic dynamics of materials provided sufficiently large single crystals are available. This requirement has limited the number of rare earth high temperature superconducting materials that have been studied in any detail. However, improvements in crystal gr