December 1999 arXiv papers — page 14

Leo Girardi

Hipparcos data has allowed the identification of a large number of clump stars in the Solar Neighbourhood. We discuss our present knowledge about their distributions of masses, ages, colours, magnitudes, and metallicities. We point out that the age distribution of clump stars is ``biased'' towards intermediate-ages. Therefore, the metallicity informa

J. Miguel Mas-Hesse, Daniel Kunth, Miguel Cervino

Wolf-Rayet stars have been detected in a large number of galaxies experiencing intense bursts of star formation. All stars initially more massive than a certain, metallicity-dependent, value are believed to experience the Wolf-Rayet phase at the end of their evolution, just before collapsing in supernova explosion. The detection of Wolf-Rayet stars puts ther

P. Morel, Ch. Morel, J. Provost, G. Berthomieu

Recent observations provide determinations of individual masses, chemical composition and metallicity of the components of the spectroscopic and interferometric binary ιPeg (Boden et al. 1998). Using updated physics, to calibrate the system, we have computed using the stellar evolutionary code CESAM, evolutionary sequences of stellar models with the masses o

C. S. Crawford, C. Vanderriest

We present integral field spectroscopy of a small sample of radio-loud quasars at intermediate redshift (0.26<z<0.60), most of which are associated with large radio sources. All have oxygen line emission extended over tens of kiloparcsecs, and these nebulae display a diverse range in both morphology and kinematic behaviour. Two quasars show &#39;plumes&#39;

Wataru Kawasaki

A catalog of nearby clusters in the 5800 deg$^2$ area in the southern Galactic cap is constructed by applying a matched-filter cluster-finding algorithm to the sample of 3.3 million galaxies from the APM Galaxy Survey. I have preliminarily detected more than 4000 cluster candidates with estimated redshift of less than 0.2 and with richness similar to those o

Jongsoo Kim, Dongsu Ryu, T. W. Jones

We investigate the nonlinear effects of uniform rotation on the Parker instability in an exponentially-stratified disk through high-resolution simulations. During the linear stage, the speed of gas motion is subsonic and the evolution with the rotation is not much different from that without the rotation. This is because the Coriolis force is small. During t

Dongsu Ryu, Francesco Miniati, Tom W. Jones, Hyesung Kang

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followe

John Lattanzio, Corinne Charbonnel, Manuel Forestini

We present a summary of the main sites for nucleosynthesis in intermediate mass Asymptotic Giant Branch (AGB) stars. We then discuss some detailed evolutionary models and how these have been used to create a synthetic evolution code which calculates the nucleosynthesis very rapidly, enabling us to investigate changes in some uncertain parameters in AGB evolu

Rosalba Perna, Lars Hernquist, Ramesh Narayan

The nature of the energy source powering anomalous X-ray pulsars is uncertain. Proposed scenarios involve either an ultramagnetized neutron star, or accretion onto a neutron star. We consider the accretion model proposed recently by Chatterjee, Hernquist & Narayan, in which a disk is fed by fallback material following a supernova. We compute the optical, inf

Eleni T. Chatzichristou

This paper is the last in a series, investigating the optical properties of a sample of mid-IR Warm Seyfert galaxies and of a control sample of mid-IR cold galaxies. In the present paper we parametrize the morphologies and interaction properties of the host galaxies and combine these with the major conclusions in our previous papers. Our results confirm that

D. I. Kosenko, K. A. Postnov

Angular fluctuations of stochastic gravitational wave backgrounds (GWB) produced by extragalactic astrophysical sources are calculated. The angular properties of such backgrounds are determined by the large scale structure of Universe (galaxy clustering). The evolution of star formation rate with redshift is taken into account. Fluctuations of the metric str

Andrew W. Blain

The first unbiased surveys for high-redshift galaxies in the submillimeter (submm) and far-infrared (FIR) wavebands have been made over the last two years. When combined with the intensity of extragalactic background radiation in the same wavebands, we have a reasonable first view of the dust enshrouded Universe. Limited spatial resolution hampers the identi

R. d&#39;Hulst, G. J. Rodgers

Models to mimic the transmission of information in financial markets are introduced. As an attempt to generate the demand process, we distinguish between dictatorship associations, where groups of agents rely on one of them to make decision, and democratic associations, where each agent takes part in the group decision. In the dictatorship model, agents segr

A. Marshakov

Duality in the integrable systems arising in the context of Seiberg-Witten theory shows that their tau-functions indeed can be seen as generating functions for the mutually Poisson-commuting hamiltonians of the {\em dual} systems. We demonstrate that the $Θ$-function coefficients of their expansion can be expressed entirely in terms of the co-ordinates of th

Alec Habig

The detection of neutrinos from SN1987A confirmed the core-collapse nature of SN II, but the neutrinos were not noticed until after the optical discovery. The current generation of neutrino experiments are both much larger and actively looking for SN neutrinos in real time. Since neutrinos escape a new SN promptly while the first photons are not produced unt

Hsin-Chia Cheng, Bogdan A. Dobrescu, Christopher T. Hill

Electroweak symmetry can be naturally broken by observed quark and gauge fields in various extra-dimensional configurations. No new {\it fundamental} fields are required below the quantum gravitational scale ($\sim$ 10 - 100 TeV). We examine schemes in which the QCD gauge group alone, in compact extra dimensions, forms a composite Higgs doublet out of (t,b)_

Hirosi Ooguri, Cumrun Vafa

We find further evidence for the conjecture relating large N Chern-Simons theory on S^3 with topological string on the resolved conifold geometry by showing that the Wilson loop observable of a simple knot on S^3 (for any representation) agrees to all orders in N with the corresponding quantity on the topological string side. For a general knot, we find a re

D0 collaboration, B. Abbott, M. Abolins

Limits on anomalous WWgamma and WWZ couplings are presented from a study of WW/WZ->enujj events in ppbar collisions at sqrt{s}=1.8 TeV. Results from the analysis of data collected using the D0 detector during the 1993-1995 Tevatron collider run at Fermilab are combined with those of an earlier study from the 1992-1993 run. A fit to the transverse momentum sp

A. W. Smith, H. M. Jaeger, T. F. Rosenbaum, A. M. Petrean

We investigate the vortex phase diagram in untwinned YBaCuO single crystals with columnar defects. These randomly distributed defects, produced by heavy ion irradiation, are expected to induce a ``Bose Glass&#39;&#39; phase of localized vortices characterized by a vanishing resistance and a Meissner effect for magnetic fields transverse to the defect axis. W

G. M. Shore, B. E. White

We give a gauge-invariant treatment of the angular momentum sum-rule for the proton in terms of matrix elements of three gauge-invariant, local composite operators. These matrix elements are decomposed into three independent form factors, one of which is the flavour singlet axial charge. The other two are interpreted as total quark and gluon angular momentum

David Djajaputra, Bernard R. Cooper

We discuss the boundary effects on a quantum system by examining the problem of a hydrogen atom in a spherical well. By using an approximation method which is linear in energy we calculate the boundary corrections to the ground-state energy and wave function. We obtain the asymptotic dependence of the ground-state energy on the radius of the well.

Michael Praehofer, Herbert Spohn

We develop a scaling theory for KPZ growth in one dimension by a detailed study of the polynuclear growth (PNG) model. In particular, we identify three universal distributions for shape fluctuations and their dependence on the macroscopic shape. These distribution functions are computed using the partition function of Gaussian random matrices in a cosine pot

D0 Collaboration, B. Abbott

Inclusive dijet production at large pseudorapidity intervals (delta_eta) between the two jets has been suggested as a regime for observing BFKL dynamics. We have measured the dijet cross section for large delta_eta in ppbar collisions at sqrt{s}=1800 and 630 GeV using the DO detector. The partonic cross section increases strongly with the size of delta_eta.

D. Anselmi

I discuss the properties of the central charges c and a for higher-derivative and higher-spin theories (spin 2 included). Ordinary gravity does not admit a straightforward identification of c and a in the trace anomaly, because it is not conformal. On the other hand, higher-derivative theories can be conformal, but have negative c and a. A third possibility

Eva Majernikova, Jaroslav Riedel, Boris A. Malomed

We consider a dc-driven damped sine-Gordon model with a small nonlinear spatial-disorder term, onto which a sinusoidal modulation is superimposed. It describes, e.g., a weakly disordered system with a regular grain structure. We demonstrate that, at the second order of the perturbation theory (with respect to the weak spatial disorder), the periodically modu

M. N. Sergeenko

The three-dimensional Schredinger&#39;s equation is analyzed with the help of the correspondence principle between classical and quantum-mechanical quantities. Separation is performed after reduction of the original equation to the form of the classical Hamilton-Jacobi equation. Each one-dimensional equation obtained after separation is solved by the convent

Jaume Garriga, Misao Sasaki

An inflating brane-world can be created from ``nothing&#39;&#39; together with its Anti-de Sitter (AdS) bulk. The resulting space-time has compact spatial sections bounded by the brane. During inflation, the continuum of KK modes is separated from the massless zero mode by the gap $m=(3/2) H$, where $H$ is the Hubble rate. We consider the analog of the Naria

S. Mossa, R. Di Leonardo, G. Ruocco, M. Sampoli

We present a realistic model of the fragile glass former orthoterphenyl and the results of extensive molecular dynamics simulations in which we investigated its basic static and dynamic properties. In this model the internal molecular interactions between the three rigid phenyl rings are described by a set of force constants, including harmonic and anharmoni

A. Prados, J. Javier Brey, B. Sanchez-Rey

Some general dynamical properties of models for compaction of granular media based on master equations are analyzed. In particular, a one-dimensional lattice model with short-ranged dynamical constraints is considered. The stationary state is consistent with Edward&#39;s theory of powders. The system is submitted to processes in which the tapping strength is

Nathan Berkovits, Carlos Tello Echevarria

An open superstring field theory action has been proposed which does not suffer from contact term divergences. In this paper, we compute the on-shell four-point tree amplitude from this action using the Giddings map. After including contributions from the quartic term in the action, the resulting amplitude agrees with the first-quantized prescription.

G. Galloway, K. Schleich, D. Witt, E. Woolgar

In gr-qc/9902061 it was shown that (n+1)-dimensional asymptotically anti-de-Sitter spacetimes obeying natural causality conditions exhibit topological censorship. We use this fact in this paper to derive in arbitrary dimension relations between the topology of the timelike boundary-at-infinity, $\scri$, and that of the spacetime interior to this boundary. We

S. T. Bramwell, K. Christensen, J. -Y. Fortin, P. C. W. Holdsworth

The probability density function (PDF) of a global measure in a large class of highly correlated systems has been suggested to be of the same functional form. Here, we identify the analytical form of the PDF of one such measure, the order parameter in the low temperature phase of the 2D-XY model. We demonstrate that this function describes the fluctuations o

J. M. Butterworth

An overview of the current data and phenomenology on the structure of the photon and an outline of some opportunities available in the medium term future.

Richard C. Brower, Benjamin Svetitsky

We apply strong-coupling perturbation theory to gauge theories containing domain-wall fermions in Shamir&#39;s surface version. We construct the effective Hamiltonian for the color-singlet degrees of freedom that constitute the low-lying spectrum at strong coupling. We show that the effective theory is identical to that derived from naive, doubled fermions w

Piero Madau, Roger D. Blandford, Martin J. Rees

Recent observations of gamma-ray bursts (GRBs) have provided growing evidence for collimated outflows and emission, and strengthened the connection between GRBs and supernovae. If massive stars are the progenitors of GRBs, the hard photon pulse will propagate in the pre-burst, dense environment. Circumstellar material will Compton scatter the prompt GRB radi

A. A. Sen

The gravitational fields of vacuumless global and gauge strings have been studied in Brans-Dicke theory under the weak field assumption of the field equations. It has been shown that both global and gauge string can have repulsive as well as attractive gravitational effect in Brans-Dicke theory which is not so in General Relativity.

I. H. Stairs, E. M. Splaver, S. E. Thorsett, D. J. Nice

Digital signal recorders are becoming widely used in several subfields of centimetre-wavelength radio astronomy. We review the benefits and design considerations of such systems and describe the Princeton Mark IV instrument, an implementation designed for coherent-dedispersion pulsar observations. Features of this instrument include corrections for the disto

M. Raible, S. G. Mayr, S. J. Linz, M. Moske

Experimental results on amorphous ZrAlCu thin film growth and the dynamics of the surface morphology as predicted from a minimal nonlinear stochastic deposition equation are analysed and compared. Key points of this study are (i) an estimation procedure for coefficients entering into the growth equation and (ii) a detailed analysis and interpretation of the

A. V. Anisovich, V. A. Sadovnikova

The nucleon-nucleon interaction in the region of the nucleon kinetic energy up to 1000 MeV is analysed together with the reaction $γd \to pn$ in the photon energy range $E_γ=0-400$ MeV. Nine nucleon-nucleon $s$-channel partial amplitudes are reconstructed in the dispersion relation $N/D$ method: $^1S_0$, $^3S_1-^3D_1$, $^3P_0$, $^1P_1$, $^3P_1$, $^3P_2$, $^1

M. I. Katsnelson, G. V. Sinko, N. A. Smirnov, A. V. Trefilov

The equations of state at room temperature as well as the energies of crystal structures up to pressures exceeding 100 GPa are calculated for Na and K . It is shown that the allowance for generalized gradient corrections (GGA) in the density functional method provides a precision description of the equation of state for Na, which can be used for the calibrat

S. Y. Choi, Jae Sik Lee

The CP properties of Higgs bosons can be probed through their s-channel resonance productions via photon-photon collisions by use of circularly and/or linearly polarized backscattered laser photons at a TeV-scale linear e^+ e^- collider. Exploiting this powerful tool, we investigate in detail the Higgs sector of the minimal supersymmetric Standard Model with

T. Gehrmann, E. Remiddi

At variance with fully inclusive quantities, which have been computed already at the two- or three-loop level, most exclusive observables are still known only at one-loop, as further progress was hampered so far by the greater computational problems encountered in the study of multi-leg amplitudes beyond one loop. We show in this paper how the use of tools a

Nobuhisa Okazaki, Junji Miyoshi, Toru Sakai

The magnetization process of the S=1/2 antiferromagnetic spin ladder at T=0 is studied by the exact diagonalization of finite clusters and size scaling analyses. It is found that a magnetization plateau appears at half the saturation value (m=1/2) in the presence of a sufficiently large next-nearest-neighbor exchange interaction to yield the frustration, whe

Carlos Castro

This report is an extension of previous one hep-th/9812189. Several quantum mechanical wave equations for $p$-branes are proposed. The most relevant $p$-brane quantum mechanical wave equations determine the quantum dynamics involving the creation/destruction of $p$-dimensional loops of topology $S^p$, moving in a $D$ dimensional spacetime background, in the

A. V. Bratchikov

The reductions of conformal field theories which lead to generalized abelian cosets are studied. Primary fields and correlation functions of arbitrary abelian coset conformal field theory are explicitly expressed in terms of those of the original theory. The coset theory has global abelian symmetry.

Shi-yuan Li, Qu-bing Xie, Qun Wang

We show that the colour-singlet process $Υ\to J/Ψ+ c\bar{c}g$ significantly contributes to the inclusive process $Υ\to J/Ψ+ X$. We calculate the partial width and the momentum distribution of the produced $J/Ψ$ in this channel. The obtained width is comparable to the experimental data. The momentum distribution is fairly soft, which is in contrast to the res

M. M. Fogler, V. M. Vinokur

We propose a dynamical theory of the stripe phase arising in a two-dimensional electron liquid near half-integral fillings of high Landau levels. The system is modelled as a novel type of a smectic liquid crystal with the Lorentz force dominated dynamics. We calculate the structure factor, the dispersion relation of the collective modes (magnetophonons), and

Jia-Lin Zhu, Rong Lu, Su-Pen Kou, Hui Hu

The quantum interference effects induced by the Wess-Zumino term, or Berry phase are studied theoretically in resonant quantum coherence of magnetization vector between degenerate excited states in nanometer-scale single-domain ferromagnets in the absence of an external magnetic field. By applying the periodic instanton method in the spin-coherent-state path

Valeri N. Kotov, Jaan Oitmaa, Oleg Sushkov, Zheng Weihong

We overview some recent work and present new results on the ground state properties and the spectrum of excitations of the two-dimensional frustrated Heisenberg antiferromagnet. Spontaneous dimer order is present in the quantum disordered phase of this model. We study the stability and analyze the structure of the spectrum, including the two-particle singlet

John N. Bahcall, Eli Waxman

Clustering of cosmic-ray sources affects the flux observed beyond the cutoff imposed by the cosmic microwave background and may be important in interpreting the AGASA, Fly&#39;s Eye, and HiRes data. The standard deviation, sigma, in the predicted number, N, of events above 10^{20} eV is sigma/N = 0.9(r_0/10 Mpc)^{0.9}, where r_0 is the unknown scale length o

A. Lima-Santos

We show explicitly how to construct the quantum Lax pair for systems with open boundary conditions. We demonstrate the method by applying it to the Heisenberg XXZ model with general integrable boundary terms.

Eliano Pessa, Giuseppe Vitiello

Inspired by the dissipative quantum model of brain, we model the states of neural nets in terms of collective modes by the help of the formalism of Quantum Field Theory. We exhibit an explicit neural net model which allows to memorize a sequence of several informations without reciprocal destructive interference, namely we solve the overprinting problem in s

M. Schreiber, D. Kilin, U. Kleinekathoefer

Based on the reduced density matrix method, we compare two different approaches to calculate the dynamics of the electron transfer in systems with donor, bridge, and acceptor. In the first approach a vibrational substructure is taken into account for each electronic state and the corresponding states are displaced along a common reaction coordinate. In the s

A. S. Holevo, R. F. Werner

We show how to compute or at least to estimate various capacity-related quantities for Bosonic Gaussian channels. Among these are the coherent information, the entanglement assisted classical capacity, the one-shot classical capacity, and a new quantity involving the transpose operation, shown to be a general upper bound on the quantum capacity, even allowin

J. Oscar Rosas-Ortiz

A supersymmetric construction of potentials describing the hard core interaction of the neutron-proton system for low energies is proposed. It considers only the binding energy case and uses the approximation of the Yukawa potential given by Hulthen. Recent experimental data for the binding energy of the deuteron are used to give the involved orders of magni

Jeff Moehlis, Stefan G. Llewellyn Smith

The radiation from the mixed layer into the interior of the ocean of near-inertial oscillations excited by a passing storm in the presence of the beta effect is reconsidered as an initial-value problem. Making use of the fact that the mixed layer depth is much smaller than the total depth of the ocean, the solution is obtained in the limit of an ocean that i

V. A. Dzuba, V. V. Flambaum, J. S. M. Ginges

Parity (P) and time (T) invariance violating effects in the Ra atom are strongly enhanced due to close states of opposite parity, the large nuclear charge Z and the collective nature of P,T-odd nuclear moments. We have performed calculations of the atomic electric dipole moments (EDM) produced by the electron EDM and the nuclear magnetic quadrupole and Schif

A. N. Ivanov, H. Oberhummer, N. I. Troitskaya, M. Faber

The Delta-Delta component of the deuteron, where Delta stands for the Delta(1232) resonance, is calculated in the relativistic field theory model of the deuteron. For the probability of the Delta-Delta component of the deuteron we give P(Delta-Delta) = 0.08 %. This prediction agrees good with the experimental estimate P(Delta-Delta) < 0.4 % at 90 % of CL (D.

R. Rosenfelder

Recent values of the proton charge radius derived from the Lamb shift in electronic hydrogen tend to be larger than those from electron scattering. Therefore low-momentum-transfer scattering data from different groups and laboratories have been reanalyzed with Coulomb and recoil corrections included. This was done by calculating at each scattering angle and

Sarmistha Banik, Debades Bandyopadhyay

We generalise the finite range momentum and density dependent Seyler-Blanchard nucleon-nucleon effective interaction to the case of interaction between two baryons. This effective interaction is then used to describe dense hadronic matter relevant to neutron stars in the nonrelativistic Thomas-Fermi approach. We investigate the behaviour of nuclear symmetry

Ben-Hao Sa, An Tai

Using a hadron-string cascade model, JPCIAE, we study the effect of nuclear deformation on J/Psi suppression in the collision of uranium nuclei at 200A GeV/c. We find that the J/Psi survival probability is much smaller if the major axes of both deformed nuclei are along the beam direction than if they are perpendicular to the beam direction.

P. Khaustov, D. E. Alburger, P. D. Barnes, B. Bassalleck

The E885 collaboration utilized the 1.8 GeV/c K^- beam line at the AGS to accumulate 3 x 10^5 (K^-,K^+) events. Xi hypernuclear states are expected to be produced through the reaction K^- + ^{12}C -> K^+ + ^{12}_{Xi}Be. The measured missing-mass spectrum indicates the existence of a signal below the threshold for free Xi production. Although the resolution w

Alexander B. Soshnikov

We prove the Central Limit Theorem for the number of eigenvalues near the spectrum edge for hermitian ensembles of random matrices. To derive our results, we use a general theorem, essentially due to Costin and Lebowitz, concerning the Gaussian fluctuation of the number of particles in random point fields with determinantal correlation functions. As another

K. R. Goodearl

Given an affine algebraic variety V and a quantization A of its coordinate ring, it is conjectured that the primitive ideal space of A can be expressed as a topological quotient of V. Evidence in favor of this conjecture is discussed, and positive solutions for several types of varieties (obtained in joint work with E. S. Letzter) are described. In particula

Kefeng Liu, Xiaonan Ma, Weiping Zhang

In this paper, we first establish a K-theory version of the equivariant family index theorem for a circle action, then use it to prove several rigidity and vanishing theorems on the equivariant K-theory level.

P. Delorme

We study Manin triples for a reductive Lie algebra, $\g$. First, we generalize results of E. Karolinsky, on the classification of Lagrangian subalgebras (cf. KAROLINSKY E., {\em A Classification of Poisson homogeneous spaces of a compact Poisson Lie group}, Dokl. Ak. Nauk, 359 (1998), 13-15). Then we show that, if $\g$ is non commutative, one can attach, to

Alexandru Dimca, Morihiko Saito

We study the algebraic Gauss-Manin system and the algebraic Brieskorn module associated to a polynomial mapping with isolated singularities. Since the algebraic Gauss-Manin system does not contain any information on the cohomology of singular fibers, we first construct a non quasi-coherent sheaf which gives the cohomology of every fiber. Then we study the al

David De Wit

This paper describes a method for the automatic evaluation of the Links-Gould two-variable polynomial link invariant (LG) for any link, given only a braid presentation. This method is currently feasible for the evaluation of LG for links for which we have a braid presentation of string index at most 5. Data are presented for the invariant, for all prime knot

Kazuyoshi Mori, Kenichi Abe

This paper is concerned with the coordinate-free approach to control systems. The coordinate-free approach is a factorization approach but does not require the coprime factorizations of the plant. We present two criteria for feedback stabilizability for MIMO systems in which transfer functions belong to the total rings of fractions of commutative rings. Both

Volker Buchholz

In this paper, the Dirac, twistor and Killing equations on Weyl manifolds with CSpin structures are investigated. A conformal Schr&#34;odinger-Lichnerowicz formula is presented and used to show integrability conditions for these equations. By introducing the Killing equation for spinors of arbitrary weight, the result of Andrei Moroianu in [9] is generalized

Nathan Berkovits

I review the construction of an action for open superstring field theory which does not suffer from the contact term problems of other approaches. I also discuss a possible generalization of this action for closed superstring field theory.

Yuri Malyuta

The $D$-brane spectra in the Type IIB string theory compactified on $AdS_{p+2}\times S^{8-p}$ are computed using the K-theory approach. The results signal the existence of the mirror-symmetry-analogue for $D$-branes, analogous to that rised in the context of derived categories.

M. Faber, A. I. Ivanov, A. Mueller, N. I. Troitskaya

The condensation of a dual-vector field is investigated in the dual Monopole Nambu-Jona-Lasinio model with dual Dirac strings. The condensate of a dual-vector field is calculated as a functional of a shape of a dual Dirac string. The obtained result is compared with the gluon condensate calculated in a QCD sum rules approach and on lattice.

Hadi Salehi

It is argued that the formal rules of correspondence between local observation procedures and observables do not exhaust the entire physical content of generally covariant quantum field theory. This result is obtained by expressing the distinguishing features of the local kinematical structure of quantum field theory in the generally covariant context in ter

M. Niedermaier, H. Samtleben

Cylindrical gravitational waves of Einstein gravity are described by an integrable system (Ernst system) whose quantization is a long standing problem. We propose to bootstrap the quantum theory along the following lines: The quantum theory is described in terms of matrix elements e.g. of the metric operator between spectral-transformed multi-vielbein config

M. L. Walker

We dispute a recent claim for a nonperturbative nonrenormalisation theorem stating that mass cannot be spontaneously generated in supersymmetric QED. We also extend a long-standing perturbative result, namely that the effective potential is zero to all orders of perturbation theory, to the nonperturbative regime for arbitrary numbers of flavours.

S. V. Molodtsov, A. M. Snigirev, G. M. Zinovjev

The phononlike excitations of (anti-)instanton ($\bar II$) liquid due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and the proper effective Lagrangian for such excitations is evaluated. The properties of their spectrum, while corresponding masses are defined by $Λ_{QCD}$, are investigated.

Stanley J. Brodsky

Several topics in QCD are reviewed, including: the light-cone Fock state representation, which encodes the flavor, spin and other quark and gluon correlations of hadrons in the form of universal process-independent amplitudes; the light-cone factorization scheme for inclusive and exclusive processes; the application of the light-cone formalism to semi-lepton

F. M. L. de Almeida, J. A. Martins Simoes

In this paper we present a calculation of the effects of bottom mixing with new exotic quarks in the forward-backward and left-right asymmetries, the bottom branching ratio and the QCD coupling constant. A global fit with the recent data on these quantities is done and stringent bounds are obtained. We discuss the effects of different isospin signatures for

Joannis Papavassiliou

The generalization of the pinch technique beyond one loop is presented. It is shown that the crucial physical principles of gauge-invariance, unitarity, and gauge-fixing-parameter independence single out at two loops exactly the same algorithm which has been used to define the pinch technique at one loop, without any additional assumptions. The two-loop cons

M. E. Sainio

A brief introduction to different determinations of the piNN coupling constant is given, and some comments on the topics discussed in the working group are made.

Joannis Papavassiliou

It is shown that the fundamental properties of gauge-independence, gauge-invariance, unitarity, and analyticity of the $S$-matrix lead to the unambiguous generalization of the pinch technique algorithm to two loops.

R. Casalbuoni, A. Deandrea, S. De Curtis, D. Dominici

In a class of models of dynamical symmetry breaking not ruled out by the available data, the lightest neutral pseudo-Nambu-Goldstone boson P0 contains only down-type techniquarks and charged technileptons. Its mass scale is naturally determined by the b-quark and therefore it is likely to be light. As the presence of pseudo-Nambu-Goldstone bosons in models o

Eef van Beveren, George Rupp

The Nijmegen Unitarized Meson Model and its application to scalar mesons is briefly revisited. It is shown that all scalar states up to 1.5 GeV can be described as triplet-P-zero quark+antiquark states coupled to the OZI-allowed open and closed two-meson channels consisting of pseudoscalar and vector mesons. Crucial are the manifestation of a resonance-doubl

U. Eichmann, C. Ernst, W. Greiner, L. Satarov

Differential spectra of coherent photon bremsstrahlung in relativistic heavy ion collisions are calculated within various schematic models of the projectile-target stopping. Two versions of the degradation length model, based on a phenomenological deceleration law, are considered. The simple shock wave model is studied analytically. The predictions of these

Parvez Anandam, Davison E. Soper

We study the factorization scheme dependence of the next-to-leading order inclusive one jet cross section d sigma/dE_T. The scheme is varied parametrically along the direction that transforms the MSbar scheme to the DIS scheme: we introduce a parameter lambda such that lambda = 0 is MSbar and lambda = 1 is DIS. The factorization scale mu is also varied. We o

Tamas G. Kovacs

I address the question of how much of QCD in the chiral limit is reproduced by instantons. After reconstructing the instanton content of smoothed Monte Carlo lattice configurations, I compare hadron spectroscopy on this instanton ensemble to the spectroscopy on the original ``physical&#39;&#39; smoothed configurations using a chirally optimised clover fermio

H. Neuberger

A brief summary of talks relating to massless lattice fermions is presented. This summary is not a review and reading it certainly is no substitute to reading the various original contributions.

Mark Lancaster

A review of recent electroweak results from hadron machines including the measurements of the top quark and W boson mass.

A. Lanaro

The aim of the DIRAC experiment at CERN is to provide an accurate determination of S-wave pion-pion scattering lengths from the measurement of the lifetime of the pi+ pi- atom. The measurement will be done with precision comparable to the level of accuracy of theoretical predictions, formulated in the context of Chiral Perturbation Theory. Therefore, the und

Y. A. Kulchitsky, M. V. Kuzmin, V. B. Vinogradov

This work is devoted to the experimental study of the longitudinal hadronic shower development in the ATLAS barrel combined prototype calorimeter consisting of the lead-liquid argon electromagnetic part and the iron-scintillator hadronic part. The results have been obtained on the basis of the 1996 combined test beam data which have been taken on the H8 beam

Reinhard Meinel

The two known exact solutions of Einstein&#39;s field equations describing rotating objects of physical significance - a black hole and a rigidly rotating disk of dust - are discussed using a single mathematical framework related to Jacobi&#39;s inversion problem. Both solutions can be represented in such a form that they differ in the choice of a complex pa

Philippos Papadopoulos, Jose A. Font

Formulations of Eulerian general relativistic ideal hydrodynamics in conservation form are analyzed in some detail, with particular emphasis to geometric source terms. Simple linear transformations of the equations are introduced and the associated equivalence class is exploited for the optimization of such sources. A significant reduction of their complexit

J. Cruz, A. Fabbri, D. J. Navarro, J. Navarro-Salas

The near extremal Reissner-Nordstrom black holes in arbitrary dimensions ca be modeled by the Jackiw-Teitelboim (JT) theory. The asymptotic Virasoro symmetry of the corresponding JT model exactly reproduces, via Cardy&#39;s formula, the deviation of the Bekenstein-Hawking entropy of the Reissner-Nordstrom black holes from extremality. We also comment how can

W. O. Putikka, M. U. Luchini, R. R. P. Singh

Using high temperature series we calculate temperature derivatives of the spin-spin and density-density correlation functions to investigate the low energy spin and charge excitations of the two-dimensional t-J model. We find that the temperature derivatives indicate different momentum dependences for the low energy spin and charge excitations. By comparing

S. Wirth, S. von Molnar

Hall crosses were used to measure the magnetic properties of arrays of ferromagnetic, nanometer-scale iron particles. The arrays typically consist of several hundred particles of 9 -- 20 nm in diameter. It is shown that the sensitivity of the measurements can be improved by matching the areas of the Hall cross and the array grown onto it by at least an order

L. Tessieri, F. M. Izrailev

We rigorously analyse the correspondence between the one-dimensional standard Anderson model and a related classical system, the `kicked oscillator&#39; with noisy frequency. We show that the Anderson localization corresponds to a parametric instability of the oscillator, with the localization length determined by an increment of the exponential growth of th

Pritiraj Mohanty

The problem of electron decoherence at low temperature is analyzed from the perspective of recent experiments on decoherence rate measurement and on related localization phenomena in low-dimensional systems. Importance of decoherence at zero temperature, perhaps induced by quantum fluctuations, is put in a broader context.

Pritiraj Mohanty

We discuss the recent experiments on persistent current in metallic rings in the backdrop of low temperature decoherence. The observed size of the persistent current, typically on the order of the Thouless energy, $ e/τ_D$, is much larger than the theoretical results, obtained with or without electron interaction. In considering the phenomenology of both dec

Jiang-Ping Hu, Shou-Cheng Zhang

The generic symmetry of a system under a uniform Zeeman magnetic field is U(1) x U(1). However, we show that SO(5) models in the presence of a finite chemical potential and a finite Zeeman magnetic field can have a exact SU(2) x U(1) symmetry. This principle can be used to test SO(5) symmetry at any doping level.