arXiv papers from November 1999

Philip C. Argyres, Sophie Pelland

We discuss the general issues and ambiguities involved in matching the exact results for the low energy effective action of scale invariant N=2 supersymmetric QCD to those obtained by instanton methods. We resolve the reported disagreements and verify agreement between an infinite series of coefficients in the low energy effective actions calculated in the t

J. C. Lopez V., A. Turbiner

Using a variational method we study a sequence of the one-electron atomic and molecular-type systems H, H_2^+, H_3^(2+) and H_4^(3+) in the presence of a homogeneous magnetic field ranging B = 0 - 4.414x10^{13} G. These systems are taken as a linear configuration aligned with the magnetic lines. For H_3^(2+) the potential energy surface has a minimum for B\s

Cristopher Moore, M. E. J. Newman

We study some simple models of disease transmission on small-world networks, in which either the probability of infection by a disease or the probability of its transmission is varied, or both. The resulting models display epidemic behavior when the infection or transmission probability rises above the threshold for site or bond percolation on the network, a

S. J. Puglia, M. J. Ramsey-Musolf

We address the impact of treating the decuplet of spin-3/2 baryons as an explicit degree of freedom in the chiral expansion of the magnetic moments of the octet of spin-1/2 baryons. We carry out a complete calculation of the octet moments to O(1/\lamchic), including decuplet contributions to the chiral loops. In contrast to results of previous analyses, we f

A. Alonso-Herrero, G. H. Rieke, M. J. Rieke, N. Z. Scoville

We present a comprehensive study of the star-formation properties of the infrared luminous galaxy Arp299 (IC694 + NGC3690). The observations include HST/NICMOS imaging and MMT optical and near-infrared spectroscopy together with HST archival data. We correct the galaxy parameters for extinction and use the results as boundary conditions for evolutionary star

A. N. Dranishnikov, T. Januszkiewicz

Coxeter groups admit amenable actions on compact spaces. Moreover, they have finite asymptotic dimension.

W. Coburn, W. A. Heindl, J. Wilms, D. E. Gruber

A failed main-on in the 35d cycle of Her X-1 was observed with the Rossi X-Ray Timing Explorer (RXTE) on 1999 April 26. Exceptions to the normal 35d cycle have been seen only twice before; in 1983 and again 1993. We present timing and spectral results of this latest Anomalous Low State (ALS) along with comparisons to the main-on and normal low states. Pulsat

C. Chicone, B. Mashhoon, D. G. Retzloff

The general phenomena associated with sustained resonance are studied in this paper in connection with relativistic binary pulsars. We represent such a system by two point masses in a Keplerian binary system that evolves via gravitational radiation damping as well as an external tidal perturbation. For further simplification, we assume that the external tida

M. Anikina, L. Chkhaidze, T. Djobava, V. Garsevanishvili

The light front analysis of pi^{-} mesons in He(Li,C), C-Ne, C-Cu and O-Pb collisions is carried out. The phase space of secondary pions is divided into two parts in one of which the thermal equilibrium assumption seems to be in a good agreement with the data. Corresponding temperatures T are extracted and their dependence on (A_{P}*A_{T})^{1/2} is studied.

J. T. Lunardi, B. M. Pimentel, R. G. Teixeira, J. S. Valverde

Two problems relative to the electromagnetic coupling of Duffin-Kemmer-Petiau (DKP) theory are discussed: the presence of an anomalous term in the Hamiltonian form of the theory and the apparent difference between the Interaction terms in DKP and Klein-Gordon (KG) Lagrangians. For this, we first discuss the behavior of DKP field and its physical components u

Shinya Kanemura

The production process of the charged Higgs-boson associated with a $W$ boson at electron-positron colliders is discussed in the two-Higgs-Doublet Model (2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is induced at one-loop level in these models. We examine how much the cross section can be enhanced by quark- and Higgs-loop effect

Richard Cleve

We consider the problem where P is an unknown permutation on {0,1,...,2^n - 1}, y is an element of {0,1,...,2^n - 1}, and the goal is to determine the minimum r > 0 such that P^r(y) = y (where P^r is P composed with itself r times). Information about P is available only via queries that yield P^x(y) from any x in {0,1,...,2^m - 1} and y in {0,1,...,2^n - 1}

D. V. Dmitriev, V. Ya. Krivnov, A. A. Ovchinnikov

The stability of the ferromagnetic phase of the 2D quantum spin-1/2 model with nearest-neighbor ferro- and next-nearest neighbor antiferromagnetic interactions is studied. It turns out that values of exchange integrals at which the ferromagnetic state becomes unstable with respect to a creation of one and two magnon are different. This difference shows that

Vassiliki Kalogera

This paper is a brief review of the topic of binary systems as sources of gravitational-wave emission for both LIGO and LISA. In particular I review the current estimates of the associated Galactic event rates and their implications for expected detection rates. I discuss the estimates for (i) the coalescence of close binaries containing neutron stars or bla

D. Lin, I. A. Smith, E. P. Liang, T. Bridgman

We report the results of our multi-wavelength observations of GRS 1758-258 made in August 1997. The energy bands include radio, millimeter, X-ray, and gamma-ray. The observations enable us to obtain a complete spectrum of the source over an energy range of 2 - 500 keV. The spectrum shows that GRS 1758-258 was in its hard state. It is well fitted by the Sunya

Eldon G. Emberly, George Kirczenow

In this paper we address the topic of inelastic electron scattering in mesoscopic quantum transport. For systems where only elastic scattering is present, Landauer theory provides an adequate description of transport that relates the electronic current to single-particle transmission and reflection probabilities. A formalism proposed recently by Bonca and Tr

Deepak Parashar, Roger J. McDermott

This paper suveys some recent algebraic developments in two parameter Quantum deformations and their Nonstandard (or Jordanian) counterparts. In particular, we discuss the contraction procedure and the quantum group homomorphisms associated to these deformations. The scheme is then set in the wider context of the coloured extensions of these deformations, na

N. I. Karchev, K. B. Blagoev, K. S. Bedell, P. B. Littlewood

In this paper we address the question of coexistence of superconductivity and ferromagnetism in the high temperature superconductor RuSr$_2$GdCu$_2$O$_{8-\delta}$. Using a field theoretical approach we study a one-fermion effective model of a ferromagnetic superconductor in which the quasiparticles responsible for the ferromagnetism form the Cooper pairs as

T. Mansour

Let T_k^m={\sigma \in S_k | \sigma_1=m}. We prove that the number of permutations which avoid all patterns in T_k^m equals (k-2)!(k-1)^{n+1-k} for k <= n. We then prove that for any \tau in T_k^1 (or any \tau in T_k^k), the number of permutations which avoid all patterns in T_k^1 (or in T_k^k) except for \tau and contain \tau exactly once equals (n+1-k)(k-1)

N. H. Brook

The parton spectra as predicted by the ARIADNE Monte Carlo generator, for both e+e- annihilation and deep inelastic scattering, are compared to the QCD MLLA calculations.

G. Papadopoulos, J. Russo, A. A. Tseytlin

We describe a simple method for generating new string solutions for which the brane worldvolume is a curved space. As a starting point we use solutions with NS-NS charges combined with 2-d CFT's representing different parts of space-time. We illustrate our method with many examples, some of which are associated with conformally invariant sigma models. Using

E. Ivanov, S. Krivonos, F. Toppan

The local Sugawara constructions of the "small" N=4 SCA in terms of supercurrents of N=2 extensions of the affinization of the sl(2|1) and sl(3) algebras are investigated. The associated super mKdV type hierarchies induced by N=4 SKdV ones are defined. In the sl(3) case the existence of two inequivalent Sugawara constructions is found. The long one involves

Idun Reiten, Michel Van den Bergh

In this paper we classify noetherian hereditary abelian categories satisfying Serre duality in the sense of Bondal and Kapranov. As a consequence we obtain a classification of saturated noetherian hereditary categories. As a side result we show that when our hereditary categories have no nonzero projectives or injectives, then the Serre duality property is e

Trinh Xuan Hoang, Marek Cieplak

We consider six different secondary structures of proteins and construct two types of Go-type off-lattice models: with the steric constraints and without. The basic aminoacid-aminoacid potential is Lennard Jones for the native contacts and a soft repulsion for the non-native contacts. The interactions are chosen to make the target secondary structure be the

Sung Won Lee

We present results for the photoproduction of inclusive prompt photons and for prompt photons accompanied by jets, measured with the ZEUS detector at HERA. Cross sections as a function of pseudorapidity and transverse energy are presented for 5 < E_T^\gamma < 10 GeV, E_T^{jet} > 5 GeV in the centre of mass energy range 120-270 GeV. Comparisons are made with

Klaus Kroy, Isabelle Capron, Madeleine Djabourov

Combining direct computations with invariance arguments, Taylor's constitutive equation for an emulsion can be extrapolated to high shear rates. We show that the resulting expression is consistent with the rigorous limits of small drop deformation and that it bears a strong similarity to an a priori unrelated rheological quantity, namely the dynamic (frequen

N. Macdonald

The dijet cross section as a function of both the fraction of the photon momentum participating in the hard process, x_\gamma^{OBS}, and the photon's virtuality, Q^2, is compared with the predictions of Herwig 5.9 for various photon parton distribution functions. The ratio of dijet cross sections with x_\gamma^{OBS} < 0.75 and x_\gamma^{OBS} > 0.75 is measur

A. Yu. Neronov

We consider cosmological models in which a homogeneous isotropic universe is embedded as a 3+1 dimensional surface into a 4+1 dimensional manifold. The size of the extra dimension depends on time. It is small compared to the size of the universe only if the energy of gravitational self-interaction of the universe through the compact extra dimension dominates

Supriya Kar

The non-commutative geometry is revisited from the perspective of a generalized D p-brane. In particular, we analyze the open bosonic string world-sheet description and show that an effective non-commutative description on a D p-brane corresponds to a re-normalized world-volume. The world-volume correlators are analyzed to make a note on the non-commutative

Ian I. Kogan, John F. Wheater

We discuss some possible relationships in gauge theories, string theory and M theory in the light of some recent results obtained in gauge invariant supersymmetric quantum mechanics. In particular this reveals a new relationship between the gauge group E_8 and 11-dimensional space.

John H. Reina, Luis Quiroga, Neil F. Johnson

We show how optically-driven coupled quantum dots can be used to prepare maximally entangled Bell and Greenberger-Horne-Zeilinger states. Manipulation of the strength and duration of the selective light-pulses needed for producing these highly entangled states provides us with crucial elements for the processing of solid-state based quantum information. Theo

N. M. Stout-Batalha, C. C. Batalha, G. S. Basri

It is widely accepted that much of the stochastic variability of T Tauri stars is due to accretion by a circumstellar disk. The emission line spectrum as well as the excess continuum emission are common probes of this process. In this communication, we present additional probes of the circumstellar environment in the form of resonance lines of low ionization

Sergio De Filippo

Only craziness I am ashamed about.

Carlo Baccigalupi, Francesca Perrotta

We predict the imprint of linear bubbly perturbations on the polarization and temperature anisotropies of the cosmic microwave background (CMB). We analytically model a bubbly density perturbation at the beginning of the radiation dominated era and we apply the linear theory of cosmological perturbations to compute its time evolution. At decoupling, it uniqu

Jerzy Lewandowski, Andrzej Okolow

We introduce a new spinorial, BF-like action for the Einstein gravity. This is a first, up to our knowledge, 2-form action which describes the real, Lorentzian gravity and uses only the self-dual connection. In the generic case, the corresponding classical canonical theory is equivalent to the Einstein-Ashtekar theory plus the reality conditions.

J. C. Lemm

Nonparametric Bayesian approaches based on Gaussian processes have recently become popular in the empirical learning community. They encompass many classical methods of statistics, like Radial Basis Functions or various splines, and are technically convenient because Gaussian integrals can be calculated analytically. Restricting to Gaussian processes, howeve

Inbo Kim, Chil-Min Kim, Won-Ho Kye, Young-Jai Park

We study the phase synchronization (PS) with type-II intermittency showing $\pm 2 \pi$ irregular phase jumping behavior before the PS transition occurs in a system of two coupled hyperchaotic R\"{o}ssler oscillators. The behavior is understood as a stochastic hopping of an overdamped particle in a potential which has $2 \pi$-periodic minima. We characterize

Abdel Pérez-Lorenzana, William A. Ponce

We look for a connection between string theories and Grand Unified Theories (GUTs), with the aim to look for new insights in the existing four dimensional string-GUT problems. We argue that the construction of consistent string-GUT models could require the use of non canonical affine levels. We list the most common level values related to realistic GUTs.

Kunegunda E. Belle, Steve B. Howell, Amy Mills

We present simultaneous X-ray (lambda_peak ~ 44A) and EUV (lambda_peak = 89A) light curves for the magnetic cataclysmic variable QQ Vulpeculae, obtained with the EUVE satellite. We find that the unique shape of the X-ray light curve is different from previously obtained X-ray light curves of QQ Vul and provides evidence for two-pole accretion. Detailed exami

G. Do Dang, A. Klein, N. R. Walet

The goal of the present account is to review our efforts to obtain and apply a ``collective'' Hamiltonian for a few, approximately decoupled, adiabatic degrees of freedom, starting from a Hamiltonian system with more or many more degrees of freedom. The approach is based on an analysis of the classical limit of quantum-mechanical problems. Initially, we stud

Stefan Weinzierl, Oleg Yakovlev

The semileptonic decay B -> pi l nu is one of the most important reactions for the determination of the CKM matrix element |V_{ub}|. However, in order to extract |V_{ub}| from data one needs an accurate theoretical calculation of the hadronic matrix element describing the B to pi transition. QCD sum rules, based on operator-product expansion on the light-con

E. Gabrielli

We perform a model independent analysis so as to constrain the leptoquark (LQ) models from negative searches for $\mu \to e \gamma$, $\mu \to 3e$ decays (and analogous processes in the $\tau$ sector), and coherent $\mu-e$ conversion in nuclei. We considerably improve some constraints obtained by analyses known in the literature, analyses which we show have b

Shoko Sakai, Dennis Zaritsky, Robert Kennicutt

We present the I-band luminosity function of the red giant branch stars in the Large Magellanic Cloud (LMC) using the data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris & Thompson, 1997). Selecting stars in uncrowded, low-extinction regions, a discontinuity in the luminosity function is observed at I_0 = 14.54 mag. Identifying this feature

Patrick Cote, Ronald O. Marzke, Michael J. West, Dante Minitti

The possibility that the Galactic spheroid was assembled from numerous chemically-distinct, proto-Galactic fragments is investigated using a Monte-Carlo technique designed to simulate the chemical evolution of the Galaxy in hierarchical formation scenarios which involve no gas dissipation. By comparing the observed and simulated metallicity distributions of

N. Macdonald

Measurements sensitive to the structure of both real and virtual photons are presented and compared to theoretical models with various photon parton distribution functions (PDFs). Measurements for real photons show a tendency for the available photon PDFs to be too small to describe the data. For virtual photons, the photon PDF is seen to decrease with incre

G. J. Wasserburg, Y. -Z. Qian

We present a model to explain the wide range of abundances for heavy r-process elements (mass number A > 130) at low [Fe/H]. This model requires rapid star formation and/or an initial population of supermassive stars in the earliest condensed clots of matter to provide a prompt or initial Fe inventory. Subsequent Fe and r-process enrichment was provided by t

Michael L. Schmid

In general relativity and electrodynamics fields are always generated from static monopoles (like mass or electric charge) or their corresponding currents by surrounding them in a spherical configuration. We investigate a generation of fields from primary fields by a scalar coupling. The generated secondary fields fulfill the condition of source-freedom and

Kimberly C. B. New, Joan M. Centrella, Joel E. Tohline

Compact astrophysical objects that rotate rapidly may encounter the dynamical ``bar instability.'' The bar-like deformation induced by this rotational instability causes the object to become a potentially strong source of gravitational radiation. We have carried out a set of long-duration simulations of the bar instability with two Eulerian hydrodynamics cod

Marco Sirianni, Antonella Nota, Claus Leitherer, Guido De Marchi

We report the result of a study in which we have used very deep broadband V and I WFPC2 images of the R136 cluster in the Large Magellanic Cloud from the HST archive, to sample the luminosity function below the detection limit of 2.8 Mo previously reached. In these new deeper images, we detect stars down to a limiting magnitude of m_F555W = 24.7 (~ 1 magnitu

Niurka R. Quintero, Angel Sanchez, Franz G. Mertens

We investigate the non-parametric, pure ac driven dynamics of nonlinear Klein-Gordon solitary waves having an internal mode of frequency $\Omega_i$. We show that the strongest resonance arises when the driving frequency $\delta=\Omega_i/2$, whereas when $\delta=\Omega_i$ the resonance is weaker, disappearing for nonzero damping. At resonance, the dynamics of

Charles Livingston, Swatee Naik

Let K be a knot in the 3-sphere with 2-fold branched covering space M. If for some prime p congruent to 3 mod 4 the p-torsion in the first homology of M is cyclic with odd exponent, then K is of infinite order in the knot concordance group. As one application, recall that the n-twisted double of an arbitrary knot has order 4 in Levine's algebraic concordance

G. S. Krishnaswami

We present a model for the structure of baryons in which the valence partons interact through a linear potential. This model can be derived from QCD in the approximation where transverse momenta are ignored. We compare the valence quark distribution function predicted by our model with that extracted from global fits to Deep Inelastic Scattering data. The on

K. Iwasawa, S. Ettori, A. C. Fabian, A. C. Edge

We report the discovery of highly distorted X-ray emission associated with the nearby cluster Zw1718.1-0108, one of whose dominant members is the powerful radio galaxy 3C353. This cluster has been missed by previous X-ray cluster surveys because of its low Galactic latitude (b = 19.5deg), despite its brightness in the hard X-ray band (2-10 keV flux of 1.2E-1

F. Igloi, R. Juhasz, H. Rieger

We study XY and dimerized XX spin-1/2 chains with random exchange couplings by analytical and numerical methods and scaling considerations. We extend previous investigations to dynamical properties, to surface quantities and operator profiles, and give a detailed analysis of the Griffiths phase. We present a phenomenological scaling theory of average quantit

F. J. Cao, H. J. de Vega

The dynamics of a dense relativistic quantum fluid out of thermodynamic equilibrium is studied in the framework of the Phi^4 scalar field theory in the large N limit. The time evolution of a particle distribution in momentum space (the tsunami) is computed. The effective mass felt by the particles in such a high density medium equals the tree level mass plus

Mario Vietri

The discovery of GRBs' afterglows has allowed us to establish several facts: their distance and energy scales, the fact that they are due to explosions, that the explosions are relativistic, and that the afterglow emission mechanism is synchrotron radiation. On the other hand, recent data have shown that the fireball model is wrong when it comes to the emiss

Patrick E. McSharry, Leonard A. Smith

A new approach to nonlinear modelling is presented which, by incorporating the global behaviour of the model, lifts shortcomings of both least squares and total least squares parameter estimates. Although ubiquitous in practice, a least squares approach is fundamentally flawed in that it assumes independent, normally distributed (IND) forecast errors: nonlin

G. E. Volovik

We discuss two exotic objects, which must be experimentally identified in chiral superfluids and superconductors. These are (i) the vortex with fractional quantum number (N=1/2 in chiral superfluids, and N=1/2 and N=1/4 in chiral superconductors), which plays the part ofthe Alice string in relativistic theories; and (ii) the hedgehog in the l-field, which is

J. Gilchrist

Dielectric permittivity of KH2PO4 single crystals and pressed powders was measured in the presence of dc electric bias fields. Usually if the bias was switched at time t = 0, real and imaginary permittivity jumped to new values then decreased as logt . This well-known 'glassy' effect is attributed to switchable microdomains that are present accidentally in s

Gennaro Corcella, Michael H. Seymour

We show vector boson transverse momentum distributions at the Tevatron, obtained by running the HERWIG Monte Carlo event generator with matrix-element corrections. We compare our results with some recent D0 and CDF data.

M. Fornari, N. Marzari, M. Peressi, A. Baldereschi

We investigate the electronic structure of over-coordinated defects in amorphous silicon via density-functional total-energy calculations, with the aim of understanding the relationship between topological and electronic properties on a microscopic scale. Maximally-localized Wannier functions are computed in order to characterize the bonding and the electron

S. Masi, P. A. R. Ade, R. Artusa, J. J. Bock

The BOOMERanG experiment is a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment features a wide focal plane with 16 detectors in the frequency bands centered at 90, 150, 220, 400 GHz, with FWHM ranging between 18 and 10 arcmin. It will be f

M. Billo', A D'Adda, P. Provero

We quantize pure 2d Yang-Mills theory on an arbitrary Riemann surface in the gauge where the field strength is diagonal. Twisted sectors originate, as in Matrix string theory, from permutations of the eigenvalues around homotopically non-trivial loops. These sectors, that must be discarded in the usual quantization due to divergences occurring when two eigen

Masanori Kohno, Masatoshi Imada

We investigate the effects of suppression of single-particle dispersion near the Fermi level on the spin gap and the singlet-pairing correlation by using the exact diagonalization method for finite-size systems. We consider strongly correlated one-dimensional models, which have flat band dispersions near wave number k=\pi/2, if the interactions are switched

Alessandro Cuccoli, Valerio Tognetti, Paola Verrucchi, Ruggero Vaia

Using the PQSCHA semiclassical method, we evaluate thermodynamic quantities of one-dimensional Heisenberg ferro- and antiferromagnets. Since the PQSCHA reduces their evaluation to classical-like calculations, we take advantage of Fisher's exact solution to get all results in an almost fully analytical way. Explicitly considered here are the specific heat, th

J. Vaitkus, E. Gaubas, V. Kazukauskas, V. Rinkevicius

Different methods of trap parameter measurement are analysed. Transient photoconductivity and thermally stimulated effects were used to investigate the influence of traps in LEC SI-GaAs and high resistivity epitaxial GaAs. The peculiarities of the TSC were analysed and shown to be related to the influence of crystal micro-inhomogeneities.

M. Maltoni, V. A. Novikov, L. B. Okun, A. N. Rozanov

The existence of extra chiral generations with all fermions heavier than M_Z is strongly disfavoured by the precision electroweak data. However the data are fitted nicely even by a few extra generations, if one allows neutral leptons to have masses close to 50 GeV. The data allow inclusion of one additional generation of heavy fermions in SUSY extension of S

Claudia Isola, T. N. Pham

We analyse the $B \to K\pi$ decays using the factorisation model with final state interaction phase shift included. We find that factorisation seems to describe qualitatively the latest CLEO data. For a test of the factorisation model, we derive a relation for the branching ratios independent of the strength of the strong penguin interactions. This relation

J. D. Bekenstein, M. Milgrom, R. H. Sanders

In a significant recent paper A. Edery undertakes a new study of light deflection in generalizations of general relativity (GR). He claims to prove that any metric-based gravitational theory that proposes to explain the flat rotation curves of disk galaxies without postulating dark matter halos must conflict with observations of gravitational lensing by gala

A. Gordon, J. E. Avron

We consider the Born-Oppenheimer problem near conical intersection in two dimensions. For energies close to the crossing energy we describe the wave function near an isotropic crossing and show that it is related to generalized hypergeometric functions 0F3. This function is to a conical intersection what the Airy function is to a classical turning point. As

I. Borukhov, D. Andelman, H. Orland

The behavior of electrolyte solutions close to a charged surface is studied theoretically. A modified Poisson-Boltzmann equation which takes into account the volume excluded by the ions in addition to the electrostatic interactions is presented. In a formal lattice gas formalism the modified Poisson-Boltzmann equation can be obtained from a mean-field approx

K. Doll, N. M. Harrison

We investigate the adsorption of chlorine on the Cu(111) surface with full potential all-electron density functional calculations. Chlorine adsorption at the fcc hollow sites is slightly preferred over that at the hcp hollow. The adsorption geometry is in excellent agreement with electron diffraction and ion scattering data. Adsorption energies and surface d

Alexander Rashkovskii

A notion of indicator for a plurisubharmonic function u of logarithmic growth in C^n is introduced and studied. It is applied to evaluation of the total Monge-Amp\`ere measure (dd^cu)^n({C}^n). Upper bounds for the measure are obtained in terms of growth characteristics of u. When u=log|f| for a polynomial mapping f with isolated zeros, the indicator generat

A. A. Arkhipov

Simple theoretical formula describing the global structure of pp and p\bar p total cross-secrions in the whole range of energies available up today has been derived. The fit to the experimental data with the formula has been made. It is shown that there is a very good correspondence of the theoretical formula to the existing experimental data.

A. T. Doyle

Analyses of event shapes and forward jet production in deep inelastic scattering at the HERA collider are described. The results are compared to QCD predictions.

Tom Busche, Peter Kopietz

We calculate the effect of a quadratic term in the energy dispersion on the low-energy behavior of the Green's function of the spinless Tomonaga-Luttinger model (TLM). Assuming that for small wave-vectors q = k - k_F the fermionic excitation energy relative to the Fermi energy is v_F q + q^2 / (2m), we explicitly calculate the single-particle Green's functio

Matteo Calandra, Sandro Sorella

We have found that the two dimensional t-J model, for the physical parameter range J/t = 0.4 reproduces the main experimental qualitative features of High-Tc copper oxide superconductors: d-wave superconducting correlations are strongly enhanced upon small doping and clear evidence of off diagonal long range order is found at the optimal doping \delta ~ 0.15

J. Böckenhauer, D. E. Evans

A braided subfactor determines a coupling matrix Z which commutes with the S- and T-matrices arising from the braiding. Such a coupling matrix is not necessarily of "type I", i.e. in general it does not have a block-diagonal structure which can be reinterpreted as the diagonal coupling matrix with respect to a suitable extension. We show that there are alway

Viktor Dotsenko

In this paper we present the exact solution for the average minimum energy of the random bipartite matching model with an arbitrary finite number of elements where random paired interactions are described by independent exponential distribution. This solution confirms the Parisi conjecture proposed for this model earlier, as well as the result of the replica

Shmuel Nussinov, Melissa A. Lampert

We review the subject of QCD inequalities, using both a Hamiltonian variational approach, and a rigorous Euclidean path integral approach.

N. N. Achasov, A. A. Kozhevnikov

Based on the Weinberg lagrangian or, in a new language, the lagrangian of hidden local symmetry added with the term induced by the anomalous lagrangian of Wess and Zumino, the dynamics of the decays rho to 4 pi and omega to 5 pi is considered. The excitation curves of rho resonance in its decay to 4 pi are obtained for the first time. The comparison with rec

Stefan Weinzierl

We report on the next-to-leading order QCD calculation for e+ e- --> 4 jets. We explain some modern techniques which have been used to calculate the one-loop amplitudes efficiently. We further report on the general purpose numerical program ``Mercutio'', which can be used to calculate any infrared safe four-jet quantity in electron-positron annihilation at n

Wei-Shu Hou, Kwei-Chou Yang

The newly observed $\bar B^0 \to \bar K^0\pi^0$ mode is quite sizable while $\pi^-\pi^+$ is rather small. Data also hint at $\pi^-\pi^0 \gtrsim \pi^-\pi^+$. Though consistent with zero, central values of CP violating asymmetries in $K^-\pi^{+,0}$ and $\bar K^0\pi^-$ show an interesting pattern. Taking cue from these, we suggest that, besides $\gamma\equiv {\

Vladimir Dragovic, Borislav Gajic

We present an L-A pair for the Apel'rot case of a heavy rigid 3-dimensional body. Using it we give an algebro-geometric integration procedure. Generalizing this L-A pair, we obtain a new completely integrable case of the Euler-Poisson equations in dimension four. Explicit formulae for integrals which are in involution are given. This system is a counterexamp

Yutaka Fujita, Tomoka Tosaki, Akika Nakamichi, Nario Kuno

We have searched for molecular gas in the cD galaxy of a poor cluster of galaxies AWM7 using Nobeyama 45 m telescope. We do not detect CO emission in the galaxy. Our limit of molecular gas in the inner 7.5 kpc is M_H_2< 4 x 10^8 M_sun. We estimate the total mass of molecular gas left in the cD galaxy when the gas deposited by a cooling flow once becomes mole

L. Hadasz, G. Lambiase, V. V. Nesterenko

The Casimir energy of a non-uniform string built up from two pieces with different speed of sound is calculated. A standard procedure of subtracting the energy of an infinite uniform string is applied, the subtraction being interpreted as the renormalization of the string tension. It is shown that in the case of a homogeneous string this method is completely

Minxin Huang, Yongde Zhang, Guang Hou

We consider the transmission of classical information over a quantum channel by two senders. The channel capacity region is shown to be a convex hull bound by the Von Neumann entropy and the conditional Von Neumann entropy. We discuss some possible applications of our result. We also show that our scheme allows a reasonable distribution of channel capacity o

C. P. Burgess, Rim Dib, Brian P. Dolan

We show that, for the transition between any two quantum Hall states, the semi-circle law and the existence of a duality symmetry follow solely from the consistency of the law of corresponding states with the two-dimensional scaling flow. This puts these two effects on a sound theoretical footing, implying that both should hold exactly at zero temperature, i

V. Dzhunushaliev, D. Singleton

Several electric/magnetic charged solutions (dyons) to 5D Kaluza-Klein gravity on the principal bundle are reviewed. Here we examine the possibility that these solutions can act as quantum virtual wormholes in spacetime foam models. By applying a sufficently large, external electric and/or magnetic field it may be possible to ``inflate'' these solutions from

I. B. Pestov

The K\"ahler-Dirac equation is derived on the Weitzenb\"ock space-time, which has a quadruplet of parallel vector fields as the fundamental structure. A consistent system of equations for the K\"ahler fields and parallel vector fields is obtained. Key words: teleparallelism, fermions, internal symmetry, equations.

Klaus Moenig

Collider measurements on electroweak physics are summarised. Although the precision on some observables is very high, no deviation from the Standard Model of electroweak interactions is observed. The data allow to set stringent limits on some models for new physics.

Shin'ichirou Yoshida, Yoshiharu Eriguchi

We have investigated an influence of the r-mode instability on hypercritically accreting ($\dot{M}\sim 1M_\odot {y}^{-1}$) neutron stars in close binary systems during their common envelope phases based on the scenario proposed by Bethe et al. \shortcite{bethe-brown-lee}. On the one hand neutron stars are heated by the accreted matter at the stellar surface,

Masaki Mori, S. A. Dazeley, P. G. Edwards, S. Gunji

The CANGAROO-III project,which consists of an array of four 10 m imaging Cherenkov telescopes,has just started being constructed in Woomera, South Australia,in a collaboration between Australia and Japan. The first stereoscopic observation of celestial high-energy gamma-rays in the 100 GeV region with two telescopes will start in 2002,and the four telescope

X. -H. Guo, A. W. Thomas, A. G. Williams

Corrections of order 1/m_Q (Q=b or c) to the Bethe-Salpeter (B-S) equation for \Lambda_Q are analyzed on the assumption that the heavy baryon \Lambda_Q is composed of a heavy quark and a scalar, light diquark. It is found that in addition to the one B-S scalar function in the limit m_Q -> \infty, two more scalar functions are needed at the order 1/m_Q. These

G. P. Rowell, T. Naito, S. A. Dazeley, P. G. Edwards

The southern supernova remnant (SNR)W28 was observed in 1994 and 1995 by the CANGAROO 3.8m telescope in a search formulti-TeV gamma ray emission, using the Cerenkov imaging technique. We obtained upper limits for a variety of point-like and extended features within a +-1 degree-region and briefly discuss these results, together with that of EGRET within the

Hidetoshi Kubo, S. A. Dazeley, P. G. Edwards, S. Gunji

CANGAROO group constructed an imaging air Cherenkov telescope (CANGAROO-II) in March 1999 atWoomera, South Australia to observe celestial gamma-rays in hundreds GeV region. It has a 7m parabolic mirror consisting of 60 small plastic spherical mirrors, and the prime focus is equipped with a multi-pixel camera of 512 PMTs covering the field of view of 3 degree

Akiko Kawachi

We have developed light and durable mirrors made of CFRP (Carbon Fiber Reinforced Plastics) laminates for the reflector of the new CANGAROO-II 7 m telescope. The reflector has a parabolic shape (F/1.1) with a 30 m^2 effective area which consists of 60 small spherical mirrors. The attitude of each mirror can be remotely adjusted by stepping motors. After the

Seiji Terashima

We derive a BPS-type bound for four-dimensional Born-Infeld action with constant B field background. The supersymmetric configuration saturates this bound and is regarded as an analog of instanton in U(1) gauge theory. Furthermore, we find the explicit solutions of this BPS condition. These solutions have a finite action proportional to the instanton number

A. A. Tseytlin, K. Zarembo

There is a close relation between classical supergravity and quantum SYM descriptions of interactions between separated branes. In the case of D3 branes, the equivalence of leading-order potentials is due to non-renormalization of the F^4 term in N=4 SYM theory. Here we point out the existence of another special non-renormalized term in quantum SYM effective

E. Harikumar, M. Sivakumar

We analyse the equivalence between topologically massive gauge theory (TMGT) and different formulations of non-topologically massive gauge theories (NTMGTs) in the canonical approach. The different NTMGTs studied are St\"uckelberg formulation of (A) a first order formulation involving one and two form fields, (B) Proca theory, and (C) massive Kalb-Ramond the