September 1997 arXiv papers — page 14

K. Kajantie, M. Laine, J. Peisa, A. Rajantie

We study the high-temperature phase of SU(2) and SU(3) QCD using lattice simulations of an effective 3-dimensional SU(N) + adjoint Higgs -theory, obtained through dimensional reduction. We investigate the phase diagram of the 3D theory, and find that the high-T QCD phase corresponds to the metastable symmetric phase of the 3D theory. We measure the Debye scr

M. Baig, J. Clua

Monopole Percolation was first introduced in the study of the non-compact lattice QED in both, the pure case and coupled to Higgs fields. Monopole percolation has been also observed coupled to the monopole condensation in the study of the pure gauge compact QED. We present here the results coming from the analysis of the role of the monopole percolation in t

Karl Jansen, Rainer Sommer

We compute the improvement coefficient $c_{sw}$ that multiplies the Sheikholeslami-Wohlert term as a function of the bare gauge coupling for two flavour QCD. We discuss several aspects concerning simulations with improved dynamical Wilson fermions.

CLEO Collaboration, M. S. Alam et al

Using data recorded by the CLEO-II detector at CESR, we report new measurements of the branching fractions for the decays of the charmed baryon $Λ_c^+$ into $pK^-π^+π^0$, $p\bar{K}^0$, $p\bar{K}^0π^+π^-$, and $p\bar{K}^0π^0$, all measured relative to $pK^-π^+$. The relative branching fractions are $0.67\pm0.04\pm0.11, 0.46\pm0.02\pm0.04,0.52\pm0.04\pm0.05$,

Thomas Hadig

The jet parton correlation has been studied for different cut scenarios and various jet algorithms. These migrations are getting important for measuring the strong coupling constant alpha_s and the NLO gluon density g(xi,Q^2) from jet rates in DIS at HERA.

Jorge Pullin

Contents: *News: April 1997 Joint APS/AAPT Meeting, by Beverly Berger The physics survey and committee on gravitational physics, by Jim Hartle *Research Briefs: Instability of rotating stars to axial perturbations, by Sharon Morsink LIGO project status, by Stan Whitcomb The Search for Frame-Dragging, by Clifford Will *Conference Reports: Conference of the So

Eric Poisson

Strong cosmic censorship holds that given suitable initial data on a spacelike hypersurface, the laws of general relativity should determine, completely and uniquely, the future evolution of the spacetime. Here it is argued that while strong cosmic censorship is enforced for all black holes residing in asymptotically flat spacetime, it is violated (within th

P. Duclos, P. Exner, B. Meller

We consider curvature-induced resonances in a planar two-dimensional Dirichlet tube of a width $ d $. It is shown that the distances of the corresponding resonance poles from the real axis are exponentially small as $ d\to 0+ $, provided the curvature of the strip axis satisfies certain analyticity and decay requirements.

W. Kramer, U. Semmelmann, G. Weingart

In a previous paper we proved a lower bound for the spectrum of the Dirac operator on quaternionic Kaehler manifolds. In the present article we show that the only manifolds in the limit case, i.e. the only manifolds where the lower bound is attained as an eigenvalue, are the quaternionic projective spaces. We use the equivalent formulation in terms of the qu

D. J. Thouless, Ping Ao, Qian Niu, M. R. Geller

We give a general review of recent developments in the theory of vortices in superfluids and superconductors, discussing why the dynamics of vortices is important, and why some key results are still controversial. We discuss work that we have done on the dynamics of quantized vortices in a superfluid. Despite the fact that this problem has been recognized as

Andrew J. Dolgert, Thomas Blum, Alan T. Dorsey, Michael Fowler

We study the localized stationary solutions of the one-dimensional time-dependent Ginzburg-Landau equations in the presence of a current. These threshold perturbations separate undercritical perturbations which return to the normal phase from overcritical perturbations which lead to the superconducting phase. Careful numerical work in the small-current limit

R. Akis, P. Vasilopoulos, P. Debray

The ballistic conductance through a device consisting of quantum wires, to which two stubs are attached laterally, is calculated assuming parabolic confining potentials of frequencies $ω_w$ for the wires and $ω_s$ for the stubs. As a function of the ratio $ω_w/ω_s$ the conductance shows nearly periodic minima associated with quasibound states forming in the

G. M. Luke, Y. Fudamoto, K. M. Kojima, M. Larkin

We have performed muon spin relaxation and susceptibility measurements of CaV_4O_9 and CaV_2O_5, systems in which spin gap-like behavior has been found. We observe spin freezing in the two compounds below 12K and 50K, respectively. Our results indicate the possibility that a substantial fraction of the of the vanadium magnetic moment is not in a spin singlet

G. Khaliullin, R. Kilian, S. Krivenko, P. Fulde

We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic- resonance Knight shift is derived, which we compare with

Mikael Fogelstrom, Sungkit Yip, Juhani Kurkijarvi

We present a self consistent treatment of pinhole junctions in $d_{x^2-y^2}$ superconductors. The current-phase relation $j_s(χ)$ is studied at different temperatures and at different angles $α$ between the crystal $\hat a$-axis and the junction (surface) normal. We show that the critical current of a junction can be reduced by pair-breaking effects at the s

M. Stopa

We show that quasi-periodic fluctuations in the charging energy E_C of small, chaotic quantum dots result from strongly scarred states which are the remnant of periodic orbits in the classical confining potential. We perform self-consistent, density functional and spin density functional calculations for the dots used in the recent experimental studies of Si

G. Caldarelli, M. Marsili, Y. -C. Zhang

A prototype model of stock market is introduced and studied numerically. In this self-organized system, we consider only the interaction among traders without external influences. Agents trade according to their own strategy, to accumulate his assets by speculating on the price's fluctuations which are produced by themselves. The model reproduced rather

Supriya Krishnamurthy, Satya N. Majumdar, Mustansir Barma

We introduce a new model of aggregation of particles where in addition to diffusion and aggregation upon contact, a single unit of mass can dissociate from a conglomerate. This dissociation move conserves the total mass and leads to a striking behaviour in the steady state. As the parameters are varied, the system undergoes a dynamical phase transition in al

S. Lubeck, M. Schreckenberg, K. D. Usadel

We consider the transition of the Nagel-Schreckenberg traffic flow model from the free flow regime to the jammed regime. We examine the inhomogeneous character of the system by introducing a new method of analysis which is based on the local density distribution. We investigated the characteristic fluctuations in the steady state and present the phase diagra

T. Cagin, G. Dereli, M. Uludogan, M. Tomak

The temperature dependence of thermodynamic and mechanical properties of six fcc transition metals (Ni, Cu, Ag, Au, Pt, Rh) and the alloying behavior of Ag-Au and Cu-Ni are studied using molecular dynamics (MD). The structures are described at elevated temperatures by the force fields developed by Sutton and co-workers within the context of tight binding app

Sanjay Puri, Alan Bray, Joel Lebowitz

We present extensive results from 2-dimensional simulations of phase separation kinetics in a model with order-parameter dependent mobility. We find that the time-dependent structure factor exhibits dynamical scaling and the scaling function is numerically indistinguishable from that for the Cahn-Hilliard (CH) equation, even in the limit where surface diffus

Mohit Randeria, Juan-Carlos Campuzano

Recent angle-resolved photoemission (ARPES) studies of the high Tc superconductors are reviewed. Amongst the topics discussed are: the spectral function interpretation of ARPES data and sum rules; studies of the momentum distribution and the Fermi surface (FS); dispersion of electronic states, flat bands and superlattice effects; unusual lineshapes and their

A. Gavrielides, V. Kovanis, P. M. Varangis, T. Erneux

We present experimental evidence for coexisting periodic attractors in a semiconductor laser subject to external optical injection. The coexisting attractors appear after the semiconductor laser has undergone a Hopf bifurcation from the locked steady state. We consider the single mode rate equations and derive a third order differential equation for the phas

Lam Hui, Robert E. Rutledge

A theory is developed which relates the observed b-parameter of a Lyman-alpha absorption line to the velocity-curvature of the corresponding peak in the optical depth fluctuation. Its relation to the traditional interpretation of b as the thermal broadening width is discussed. It is demonstrated that, independent of the details of the cosmological model, the

Soeren Madsen, Andrei G. Doroshkevich, Stefan Gottloeber, Volker Müller

The large scale gravitational potential distribution and its influence on the large-scale matter clustering is considered on the basis of six simulations. It is found that the mean separation between zero levels of the potential along random straight lines coincides with the theoretical expectations, but it scatters largely. A strong link of the initial pote

Roger Coziol, André L. B. Ribeiro, Reinaldo R. de Carvalho, Hugo V. Capelato

We present the results of the spectral classification of the 82 brightest galaxies in a sample of 17 compact groups. We verify that the AGNs are preferentially located in the most early-type and luminous galaxies of the groups, as is usually observed in the field. But these AGNs also appear to be systematically concentrated towards the central parts of the g

Karen M. Leighly, Laura E. Kay, Beverley J. Wills, D. Wills

We report the detection of ionized absorption in the ASCA spectrum of the narrow-line Seyfert 1 galaxy IRAS 17020+4544. Subsequent optical spectropolarimetry revealed high polarization increasing from 3% in the red to 5% in the blue, indicating electron or dust scattering as a likely origin. The broad emission line H$α$ is somewhat less polarized than the co

P. Goldoni, A. Goldwurm, P. Laurent, F. Lebrun

The Imager on Board Integral Satellite (IBIS) is the imaging instrument of the INTEGRAL satellite, the hard-X/soft-gamma ray ESA mission to be launched in 2001. It provides diagnostic capabilities of fine imaging (12' FWHM), source identification and spectral sensitivity to both continuum and broad lines over a broad (15 keV--10 MeV) energy range. It has

T. Foglizzo, R. A. Garcia, P. Boumier, J. Charra

We have studied the statistical properties of the energy of individual acoustic modes, extracted from 310 days of GOLF data near the solar minimum. The exponential distribution of the energy of each mode is clearly seen. The modes are found to be uncorrelated with a +-0.6 % accuracy, thus supporting the hypothesis of stochastic excitation by the solar convec

Lars Bildsten

Neutron stars in mass-transferring binaries are accreting the hydrogen and helium rich matter from the surfaces of their companions. This article simply explains the physics associated with how that material eventually fuses to form heavier nuclei and the observations of the time dependent phenomena (such as Type I X-ray bursts) associated with the thermally

V. V. Sokolov, A. I. Kopylov, S. V. Zharikov, E. Costa

We report results of follow-up multicolor photometry of the optical variable source that is a probable remnant of the gamma-ray burst GRB970508 discovered by the BeppoSAX satellite (IAUC 6649). Observations were carried out in Johnson-Kron-Cousins $ BVR_cI_c system with the 1-m and 6-m telescopes of SAO RAS. Between the 2nd and the 5th day after the burst a

Adriano H. Cerqueira, Elisabete M. de Gouveia Dal Pino, Marc Herant

We present the results of 3-D SPMHD numerical simulations of supermagnetosonic, overdense, radiatively cooling jets. Two initial magnetic configurations are considered: (i) a helical and (ii) a longitudinal field. We find that magnetic fields have important effects on the dynamics and structure of radiative cooling jets, especially at the head. The presence

P. Goldoni, M. Vargas, A. Goldwurm, P. Laurent

We report on hard X-ray observations of X-ray Nova Velorum 1993 (GRS 1009-45) performed with the SIGMA coded mask X-ray telescope in January 1994. The source was clearly detected with a flux of about 60 mCrab in the 40-150 keV energy band during the two observations with a hard spectrum (alpha ~ - 1.9) extending up to ~ 150 keV. These observations confirm th

David Merritt, Monica Valluri

The motion of stars in the gravitational potential of a triaxial galaxy is generically chaotic. However, the timescale over which the chaos manifests itself in the orbital motion is a strong function of the degree of central concentration of the galaxy. Here, chaotic diffusion rates are presented for orbits in triaxial models with a range of central density

Anuradha Koratkar, Elena Pian, C. Megan Urry, Joseph E. Pesce

The blazar 3C 279 is well studied and shows frequent large continuum flares from radio to gamma-ray wavelengths. There have been a number of multi-wavelength observations of 3C 279, and hence there are many ultraviolet data for this object available in the UV archives. In this paper we present Ly alpha emission line measurements for 3C 279 using all the arch

Luigi Stella, Mario Vietri

We show in this Letter that relativistic dragging of inertial frames around fast rotating collapsed stars is substantial and can give rise to observable effects. We apply this to the kHz quasi periodic oscillations (QPOs) sources, low mass X-ray binaries (LMXRBs) containing an accreting neutron star. Within the beat frequency model, both the Keplerian freque

H. M. Antia, Sarbani Basu, S. M. Chitre

A new set of accurately measured frequencies of solar oscillations are used to infer the rotation rate inside the Sun, as a function of radial distance as well as latitude. We have adopted a regularized least squares technique with iterative refinement for both 1.5D inversion using the splitting coefficients and 2D inversion using individual m splittings. Th

J. Liske, J. K. Webb

The spatial distribution of Ly-alpha forest absorption systems toward a group of 8, closely spaced QSOs has been analysed and evidence for large scale structure has been found at <z> = 2.8. Our technique is based on the first and second moments of the transmission probability density function which is capable of identifying and assessing the significance of

Paul H. Frampton, Bettina Keszthelyi, Y. Jack Ng

It is proposed that the highest energy $\sim 10^{20}$eV cosmic ray primaries are protons, decay products of a long-lived progenitor which has propagated from typically $\sim 100$Mpc. Such a scenario can occur in e.g. SU(15) grand unification and in some preon models, but is more generic; if true, these unusual cosmic rays provide a window into new physics.

Rainer Fuhrmann, Fernando Torres

We use Weierstrass Point Theory and Frobenius orders to prove the uniqueness (up to isomorphism) of some optimal curves.

Richard Earl, Frances Kirwan

The cohomology of the moduli spaces of stable bundles M(n,d), of coprime rank n and degree d, over a Riemann surface (of genus g > 1) have been intensely studied over the past three decades. We prove in this paper that the Pontryagin ring of M(n,d) vanishes in degrees above 2n(n-1)(g-1) and that this bound is strict (i.e. there exists a non-zero element of d

Bogdan A. Dobrescu, John Terning

We show that an effective field theory that includes non-standard couplings between the electroweak gauge bosons and the top and bottom quarks may yield negative contributions to both the S and T oblique radiative electroweak parameters. We find that that such an effective field theory provides a better fit to data than the standard model (the chi-squared pe

Kamales Kar, Sukhendusekhar Sarkar, Srubabati Goswami, Amitava Raychaudhuri

In Gallium detectors for solar neutrinos, the capture rate due to Gamow-Teller transitions to excited states of 71Ge beyond the neutron emission threshold is usually neglected. We make a model calculation to estimate its effect and find that this yields an additional contribution which may be as much as 0.4 SNU, even larger than that from the Isobaric Analog

B. B. Beard, R. J. Birgeneau, M. Greven, U. -J. Wiese

The correlation length of the square-lattice spin-1/2 Heisenberg antiferromagnet is studied in the low-temperature (asymptotic-scaling) regime. Our novel approach combines a very efficient loop cluster algorithm -- operating directly in the Euclidean time continuum -- with finite-size scaling. This enables us to probe correlation lengths up to $ξ\approx 350,

L. J. Boya, H. C. Rosu, A. J. Segui-Santonja, J. Socorro

The Schrödinger equation with attractive delta potential has been previously studied in the supersymmetric quantum mechanical approach by a number of authors, but they all used only the particular superpotential solution. Here, we introduce a one-parameter family of strictly isospectral attractive delta function potentials, which is based on the general supe

Xiao-Gang Wen, Patrick A. Lee

The microscopic theory of superconducting (SC) state in the SU(2) slave-boson model is developed. We show how the pseudogap and Fermi surface (FS) segments in the normal state develop into a d-wave gap in the superconducting state. Even though the superfluid density is of order x (the doping concentration), the physical properties of the low lying quasiparti

Jeff Secker, William E. Harris, Julia D. Plummer

We study the dwarf galaxy population in the central ~700 arcmin^2 of the Coma cluster, the majority of which are early-type dwarf elliptical (dE) galaxies. Analysis of the statistically-decontaminated dE galaxy sequence in the color-magnitude diagram reveals a highly significant trend of color with magnitude (Δ(B-R)/ΔR = -0.056\pm0.002 mag), in the sense tha

J. C. Niemeyer, K. Jedamzik

The recent discovery of critical phenomena arising in gravitational collapse near the threshold of black hole formation is used to estimate the initial mass function of primordial black holes (PBHs). It is argued that the universal scaling relation between black hole mass and initial perturbation found for a variety of collapsing space-times also applies to

J. Main, G. Wunner

Gutzwiller&#39;s trace formula for the semiclassical density of states diverges at the bifurcation points of periodic orbits and has to be replaced with uniform semiclassical approximations. We present a method to derive these expressions from the standard representations of the elementary catastrophes and to directly relate the uniform solutions to classica

J. Main, V. A. Mandelshtam, G. Wunner, H. S. Taylor

In semiclassical theories for chaotic systems such as Gutzwiller&#39;s periodic orbit theory the energy eigenvalues and resonances are obtained as poles of a non-convergent series g(w)=sum_n A_n exp(i s_n w). We present a general method for the analytic continuation of such a non-convergent series by harmonic inversion of the &#34;time&#34; signal, which is

The Baikal Collaboration

We review the present status of the Baikal Deep Underwater Neutrino Experiment. The construction and performance of the large deep underwater Cherenkov detector for muons and neutrinos, NT-200 (Neutrino Telescope with 200 phototubes), which is currently under construction in Lake Baikal are described. Some results obtained with the intermediate detectors NT-

F. del Aguila, A. Culatti, R. Munoz-Tapia, M. Perez-Victoria

We present a procedure of differential renormalization at the one loop level which avoids introducing unnecessary renormalization constants and automatically preserves abelian gauge invariance. The amplitudes are expressed in terms of a basis of singular functions. The local terms appearing in the renormalization of these functions are determined by requirin

You-Quan Li, Christian Gruber

By introducing a boundary condition for the quantum wire, the Hubbard model is solved exactly by means of Bethe ansatz. The wave function for the bounded state is clearly defined, and the secular equation for the spectrum is exactly obtained. The ground state and low-lying excited states are studied in the thermodynamic limit. The ground-state energy in the

I. P. Ennes, P. Ramadevi, A. V. Ramallo, J. M. Sanchez de Santos

We study the crossing symmetry of the conformal blocks of the conformal field theory based on the affine Lie superalgebra osp(1|2). Within the framework of a free field realization of the osp(1|2) current algebra, the fusion and braiding matrices of the model are determined. These results are related in a simple way to those corresponding to the su(2) algebr

Nobuyoshi Ohta, Jian-Ge Zhou

An explicit solution in super Yang-Mills theory, which after T-duality describes two sets of D4-branes at angles, is constructed. The gauge configuration possesses 3/16 unbroken supersymmetry for the equal magnitudes of field strengths, and can be considered as the counterpart of the solution of D=11 supergravity with the same amount of supersymmetry in the

Kiwoon Choi, Jae Sik Lee, Carlos Munoz

We compute quadratically divergent supergravity one-loop effects on soft supersymmetry-breaking parameters and the $μ$ term in generic hidden sector supergravity models. These effects can significantly modify the matching condition for soft parameters at the Planck scale and also provide several new sources of the $μ$ term which are naturally of order the we

Wayne Hu, Uros Seljak, Martin White, Matias Zaldarriaga

We generalize the total angular momentum method for computing Cosmic Microwave Background anisotropies to Friedman-Robertson-Walker (FRW) spaces with arbitrary geometries. This unifies the treatment of temperature and polarization anisotropies generated by scalar, vector and tensor perturbations of the fluid, seed, or a scalar field, in a universe with const

Pedro F. Gonzalez-Diaz

We discuss some arguments in favour of the proposal that the quantum correlations contained in the pure state-vector evolving according to Schoedinger equation can be eliminated by the action of multiply connected wormholes during measurement. We devise a procedure to obtain a proper master equation which governes the changes of the reduced density matrix of

Hitoshi Konno

We introduce an elliptic algebra $U_{q,p}(\hat{sl_2})$ with $p=q^{2r} (r\in \R_{>0})$ and present its free boson representation at generic level $k$. We show that this algebra governs a structure of the space of states in the $k-$fusion RSOS model specified by a pair of positive integers $(r,k)$, or equivalently a $q-$deformation of the coset conformal field

C. Sanchez, S. A. Dassie, A. M. Baruzzi, E. P. M. Leiva

A series of calculations on the energetics of complexation of alkaline metals with 1,10-phenanthroline are presented. It is an experimental fact that the ordering of the free energy of transfer across the water - 1,2-dichloroethane interphase is governed by the charge / size ratio of the diferent cations; the larger cations showing the lower free energy of t

D. Raparia, J. Alessi, A. Kponou

Projections of charged particle beam current density (profiles) are frequently used as a measure of beam position and size. In conventional practice only two projections, usually horizontal and vertical, are measured. This puts a severe limit on the detail of information that can be achieved. A third projection provides a significant improvement. The Algebra

D. Raparia, J. Alessi, Y. Y. Lee, W. T. Weng

In the National Spallation Neutron Source (NSNS) design, a 180 meter long transport line connects the 1 GeV linac to an accumulator ring. The linac beam has a current of 28 mA, pulse length of 1 ms, and 60 Hz rep rate. The high energy transport line consists of sixteen 60 degrees FODO cells, and accommodates a 90 degrees achromatic bend, an energy compressor

G. A. Lalazissis, D. Vretenar, W. Poeschl, P. Ring

The isospin dependence of the spin-orbit interaction in light neutron rich nuclei is investigated in the framework of relativistic mean field theory. The magnitude of the spin-orbit potential is considerably reduced in drip line nuclei, resulting in smaller energy splittings between spin-orbit partners. The effect does not depend on the parametrization of th

Liang-gang Liu, Masahiro Nakano

We put forward a formalism to calculate the relativistic particle - hole and delta - hole excitation polarization insertion for pion propagator by using the particle - hole - antiparticle representation of nucleon and delta propagators in nuclear matter. The real and the imaginary part of the polarization insertion and the dispersion relation for pion propag

V. B. Belyaev, D. E. Monakhov, N. Shevchenko, S. A. Sofianos

We consider several nuclear fusion reactions that take place at the center of the sun, which are omitted in the standard pp-chain model. More specifically the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei in triple collisions involving electrons are estimated within the framework of the adiabatic approximation. These rates are c

V. Pascalutsa, J. A. Tjon

We present a unitary relativistic quasi-potential model for describing the low-energy pion-nucleon interaction, based on the equal time Bethe-Salpeter equation. It preserves the covariant structure of a relativistic spin 1/2 particle for the nucleon propagator, to be contrasted to other quasi-potential approximations.

Hao-Shiung Lin, Oktay K. Pashaev, Shi-Shyr Roan

We establish the isomorphism between a nonlinear $σ$-model and the abelian gauge theory on an arbitrary curved background, which allows us to derive integrable models and the corresponding Lax representations from gauge theoretical point of view. In our approach the spectral parameter is related to the global degree of freedom associated with the conformal o

Shao-shiung Lin, Oktay K. Pashaev, Shi-shyr Roan

We establish the isomorphism between a nonlinear $σ$-model and the abelian gauge theory on an arbitrary curved background, which allows us to derive integrable models and the corresponding Lax representations from gauge theoretical point of view. In our approach the spectral parameter is related to the global degree of freedom associated with the conformal o

N. Dorey, T. J. Hollowood, V. V. Khoze, M. P. Mattis

Extending recent N=1 and N=2 results, we propose an explicit formula for the integration measure on the moduli space of charge-n ADHM multi-instantons in N=4 supersymmetric SU(2) gauge theory. As a consistency check, we derive a renormalization group relation between the N=4, N=2, and N=1 measures. We then use this relation to construct the purely bosonic (`

Noureddine Mohammedi

Non-Abelian duality transformations built on non-semi-simple isometry groups are analysed. We first give the conditions under which the original non-linear sigma model and its non-Abelian dual are equivalent. The existence of an invariant and non-degenerate bilinear form for the isometry Lie algebra is crucial for this equivalence. The non-Abelian dual of a

Tomasz Brzezinski, Houari Merabet

A method of deriving solutions to Nahm&#39;s equations based on root structure of simple Lie algebras is given. As an illustration of this method the recently found solutions to Nahm&#39;s equations with tetrahedral and octahedral symmetries are shown to correspond to $A_2$ and $A_3$ root systems.

Renata Kallosh

A general set of rules is given how to convert a local kappa-symmetry of a brane action and space-time supersymmetry into the global supersymmetry of the worldvolume. A Killing spinor adapted gauge for quantization of kappa-symmetry is defined for this purpose. As an application of these rules we perform the gauge-fixing of the M-5-brane to get the theory of

M. J. Cassidy, S. W. Hawking

In this paper, we derive an expression for the grand canonical partition function for a fluid of hot, rotating massless scalar field particles in the Einstein universe. We consider the number of states with a given energy as one increases the angular momentum so that the fluid rotates with an increasing angular velocity. We find that at the critical value wh

A. A. Natale, P. S. Rodrigues da Silva

We show that if a gauge theory with dynamical symmetry breaking has non-trivial fixed points, they will correspond to extrema of the vacuum energy. This relationship provides a different method to determine fixed points.

T. P. Cheng, Ling-Fong Li

The chiral quark model suggests that the baryon quark-sea is negatively polarized. This modifies the spin structure as given by the naive quark model and agrees with experimental data. However, for the magnetic moments, there is significant cancellation between the contritutions from this sea spin-polarization and the orbital angular momentum so that effecti

J. O. Andersen

Massless scalar electrodynamics is studied at high temperature and zero chemical potential. I derive the free energy to order $λ^2$, $λe^2$ and $e^4$ by effective field theory methods. The first step consists of the construction of an effective three-dimensional field theory that is valid on distance scales $R\gg 1/T$ and whose parameters can be written as p

Ling-Fong Li, T. P. Cheng

After a pedagogical review of the simple constituent quark model and deep inelastic sum rules, we describe how a quark sea as produced by the emission of internal Goldstone bosons by the valence quarks can account for the observed features of proton spin and flavor structures. Some issues concerning the strange quark content of the nucleon are also discussed

A. Bottino, F. Donato, N. Fornengo, S. Scopel

We analyze the properties of neutralino under the hypothesis that some preliminary experimental results of the DAMA/NaI Collaboration may be indicative of a yearly modulation effect. We examine which supersymmetric configurations would be singled out by the DAMA/NaI data. We also discuss the possibility to investigate these configurations by means of experim

Robert Fleischer

Recent developments concerning CP violation beyond the Standard Model are reviewed. The central target of this presentation is the $B$ system, as it plays an outstanding role in the extraction of CKM phases. Besides a general discussion of the appearance of new physics in the corresponding CP-violating asymmetries through $B^0_q$--$\bar{B^0_q}$ mixing $(q\in

D. Seckel

At energies above the threshold for $W$ production the process $νγ\to l W^+$ is competive with $νν$ scattering at the same center of mass energies. In a cosmological setting, absorption of ultra high energy neutrinos by the microwave photon background is comparable to absorption by the neutrino background. In passing through matter, the process $ν\to l W^+$

Srinath Cheluvaraja

We study the three-dimensional SU(2) lattice gauge theory at finite temperature using an observable which is dual to the Wilson line. This observable displays a behaviour which is the reverse of that seen for the Wilson line. It is non-zero in the confined phase and becomes zero in the deconfined phase. At large distances, it&#39;s correlation function falls

M. Gürtler, E. -M. Ilgenfritz, A. Schiller, C. Strecha

The electroweak phase transition is investigated near to its endpoint in the framework of an effective three-dimensional model. We measure the very weak interface tension with the tunneling correlation length method. First results for the mass spectrum and the corresponding wave functions in the symmetric phase are presented.

M. Gürtler, E. -M. Ilgenfritz, A. Schiller

The 3d SU(2)-Higgs model is used to find the critical Higgs mass above which the first order phase transition ends. One method is focused on the disappearance of the two-state signal of the scalar condensate (vanishing of the latent heat). Another method is based on the analysis of Lee-Yang zeroes of the partition function which allows to characterise the ch

C. B. Lang, T. K. Pany

We determine non-perturbatively a fixed-point (FP) action for fermions in the two-dimensional U(1) gauge (Schwinger) model. Our parameterization for the fermionic action has terms within a $7\times 7$ square on the lattice, using compact link variables. With the Wilson fermion action as starting point we determine the FP-action by iterating a block spin tran

Martin Zach, Manfried Faber, Peter Skala

We investigate singly and doubly charged flux tubes in U(1) lattice gauge theory. By simulating the dually transformed path integral we are able to consider large flux tube lengths, low temperatures, and multiply charged systems without loss of numerical precision. We simulate flux tubes between static sources as well as periodically closed flux tubes, calcu

M. Goeckeler, R. Horsley, V. Linke, H. Perlt

Continuing our investigations of quenched QCD with improved fermions we have started simulations for lattice size 32^3 x 64 at beta=6.2. We present first results for light hadron masses at kappa=0.13520, 0.13540, and 0.13555. Moreover we compare our initial experiences on the T3E with those for APE/Quadrics systems.

P. N. Burrows

Measurements of alpha_s from e+e- annihilation experiments are reviewed and compared with measurements from other processes. Highlights are presented of recent QCD studies in e+e- annihilation at the Z0 resonance.

Mathias Trucks

In this work we define a new state on the Weyl algebra of the free massive scalar Klein-Gordon field on a Robertson-Walker spacetime and prove that it is a Hadamard state. The state is supposed to approximate a thermal equilibrium state on a Robertson-Walker spacetime and we call it an adiabatic KMS state. This opens the possibility to do quantum statistical

E. W. Carlson, S. A. Kivelson, Z. Nussinov, V. J. Emery

The ground-state properties of the t-J model on a d-dimensional hypercubic lattice are examined in the limit of large d. It is found that the undoped system is an ordered antiferromagnet, and that the doped system phase separates into a hole-free antiferromagnetic phase and a hole-rich phase. The latter is electron free if J > 4t and is weakly metallic (and

K. Hallberg, C. D. Batista, A. A. Aligia

We calculate the specific heat of the antiferromagnetic spin-1 chain compound Y_2BaNi_{1-x}Zn_xO_5 in the presence of a magnetic field. The low-energy spectrum of a Heisenberg Hamiltonian, which includes realistic anisotropies, has been solved using the density matrix renormalization group. The observed Schottky anomaly is very well described by this theory.

P. A. Marchetti, Zhao-bin Su, Lu Yu

The $U(1)\times SU(2)$ Chern-Simons gauge theory is applied to study the 2-D $t-J$ model describing the normal state of underdoped cuprate superconductors. The U(1) field produces a flux phase for holons converting them into Dirac-like fermions, while the SU(2) field, due to the coupling to holons gives rise to a gap for spinons. An effective low-energy acti

A. Lucke, C. H. Mak, R. Egger, J. Ankerhold

The observability of electronic coherence in electron transfer reactions is discussed. We show that under appropriate circumstances large-amplitude oscillations can be found in the electronic occupation probabilities. The initial preparation of the system is of crucial importance for this effect, and we discuss conditions under which experiments detecting el

F. Slanina, M. Kotrla

We study the influence of a point defect on the profile of a growing surface in the single-step growth model. We employ the mapping to the asymmetric exclusion model with blockage, and using Bethe-Ansatz eigenfunctions as a starting approximation we are able to solve this problem analytically in two-particle sector. The dip caused by the defect is computed.

Raquel Dominguez-Cascante

Information theory is used to perform a thermodynamic study of non equilibrium anisotropic radiation. We limit our analysis to a second-order truncation of the moments, obtaining a distribution function which leads to a natural closure of the hierarchy of radiative transfer equations in the so-called variable Eddington factor scheme. Some Eddington factors a

M. S. L. du Croo de Jongh, J. M. J. van Leeuwen

We have adjusted the Density Matrix Renormalization method to handle two dimensional systems of limited width. The key ingredient for this extension is the incorporation of symmetries in the method. The advantage of our approach is that we can force certain symmetry properties to the resulting ground state wave function. Combining the results obtained for sy

D. Sornette

Stochastic processes with multiplicative noise have been studied independently in several different contexts over the past decades. We focus on the regime, found for a generic set of control parameters, in which stochastic processes with multiplicative noise produce intermittency of a special kind, characterized by a power law probability density distributio

Giovanni Gallavotti

We provide an illustration of a mechanism for Arnold&#39;s diffusion following a nonvariational approach and find explicit estimates for the diffusion time.

Jonas Lundbek Hansen, Tomas Bohr

We study the motion of passive tracers in a two-dimensional turbulent velocity field generated by the Kuramoto-Sivashinsky equation. By varying the direction of the velocity-vector with respect to the field-gradient we can continuously vary the two Lyapunov exponents for the particle motion and thereby find a regime in which the particle distribution is a st

Miguel H. Iba~nez S.

The linear stability analysis of an optically thin plasma where a general reaction proceeds, including chemical relaxation time effects, is carried out . A fifth order dispersion equation (instead of the fourth order one resulting when such effects are neglected) is obtained. The new mode with the corresponding instability criterion as well as the modificati

Stephen P. Boughn

We present cross-correlation analyses of the HEAO 2-10 keV diffuse X-ray map with both the combined GB6/Parkes-MIT-NRAO (GB6-PMN) 5 GHz and the FIRST 1.4 GHz radio surveys. The cross-correlation functions (CCFs) of both radio surveys with the unresolved X-ray background were detected at the 5 sigma level. While the large angular resolution (3 degrees) of the